 Good morning friends. In our previous lectures, we have learnt about sand casting. We have seen how to make the sand mold and how to get the sand casting. Then we have learnt about casting defects. Then we have learnt about melting and pouring practices. Then we have learnt about important cast metals and alloys. Now today we will switch over to another important phase of metal casting that is the die casting process. Now what is this die casting? Why we should go for die casting? Let us see. First of all what is the drawback of sand molding process? Why we should go what say leave sand molding and why we should switch over to die casting? In the case of the sand casting a separate mold has to be made in each and every case. If we want to make a sand casting initially we have to make the pattern then we have to make the mold then we pour the molten metal. Once we pour the molten metal once the molten metal is solidified we break that sand mold and the mold is no more permanent. If we want to make another casting again we have to make another mold and we have to pour. Likewise in each and every case we have to make a separate mold. So this involves lot of labor and also it increases the cost of production and also productivity will be lesser. Now to overcome these drawbacks this what say die casting has been developed. So in the case of the now let us come to the specialty of the die casting process. Now in the case of the die casting process instead of a sand mold a metallic mold is used in the place of sand mold with which large number of castings are made means this is a metallic mold remember. So this metallic mold we are not going to break after this verification of the casting same mold will be used again and again for making several castings. So this metallic mold is known as die. Now here the mold material is metal or alloy. Now we have seen that in the case of the die casting process a metallic mold will be used and the same metallic mold will be used to make thousands and thousands of castings. Now types of die casting process what are the types one is the gravity die casting process this is also known as permanent molding process means here no doubt the metallic molds will be used there would not be any sand molds but molten metal will be poured into these metallic molds by virtue of gravity. So that is why it is known as the gravity die casting means we would not apply any external pressure so that is the dry gravity die casting. The second one is the pressure die casting in the case of the gravity die casting the molten metal enters into the metallic molds by virtue of gravity whereas here in the case of the pressure die casting the molten metal will be entering into the metallic molds because of the external pressure we apply. So that is why these two are different again the pressure die casting is two types one is the cold chamber pressure die casting second one is the hot chamber pressure die casting. In the case of the cold chamber pressure die casting yes there will be metallic molds will be there yes we inject the molten metal into the metallic molds but we need molten metal we need to prepare the molten metal for that we need a furnace this furnace is separate from the machine cold chamber die casting machine it will be away from the machine. Whereas in the case of the hot chamber pressure die casting machine yes again here there will be metallic molds and we apply external pressure to inject the molten metal inside the dies but the furnace in which we make the molten metal is an integral part of the die casting machine that way hot chamber pressure die casting machine is different from cold chamber pressure die casting machine. Now we will be seeing all these one by one so first we will see gravity die casting or it is also known as the permanent molding process. Now what is the history of the permanent molding process? The first permanent mold castings were made using stone molds sometime around 2000 BC this was in practice even during BC but that time metallic molds were not used people used sand molds between the sand molds they were pouring the molten metal by virtue of gravity this process was used to cast tools out of copper those days. Now the discovery of iron and the ability to forge the cast iron led to permanent molds made from iron which were mostly used for to cast bronze. Now later man has what is a what is it lent how to what is a extract iron how to melt iron and how to forge iron components with that they even made permanent molds permanent metallic molds made up of iron so these were used to cast bronze. Now what is the status today today permanent molds are made from a range of materials including iron steel and graphite. So these are the molding materials today the molding materials mold materials are made up of iron steel and graphite a wide range of metals are cast in these permanent molds now what are the what is a cast metals that are what is a cast in these molds several materials several non ferrous materials can be cast using these what is a molds. Now first we will see we will be learning about the gravity die casting what are the steps involved in this process and here we can see there are two molds will be there so these are the metallic molds. So one mold is a stationary mold the other mold is a movable mold so here this is the what is a stationary mold see here this is the cavity this is the cavity. Now this is the movable mold and this is also the cavity now when we close these two what will happen inside there will be a cavity what say so that cavity resembles the shape of the casting which we are going to produce. Now initially these two what say dies will be kept apart then you can see here spray will be what say put on the cavity surface. Now here we can see this is the hydraulic cylinder to open and close the movable mold. So this cylinder operates hydraulically and it exerts what say intensive pressure so that this mold will be moving forward and backward. So initially the mold is preheated and coated next what will happen these two molds will be closed then what happened say there is a cavity this will be further closed you can see here now it is about to close so this will be further close then there will be a cavity is there you can see this is the cavity. So this is the what say shape of the casting which we want now if we want here recess inside the casting we can place a core so this is a core so cores if used are inserted and the mold is fully closed then the die will be fully closed again you see here pressure will be upright so that die two dies will be closed fully then what will happen here you can see the dies are fully closed and there is no gap between the fixed mold and the movable mold here you can see there is no gap. Now the molten metal is poured into the mold where it solidifies so this is the what say crucible in which there is molten metal now the molten metal is being poured now the molten metal enters into the cavity yes it flows around the core then it comes down then after sometime the molten metal will be solidifying and here we can see pouring of molten metal into the gravity cast molds it is being poured so this is one die and this is one die now this is the ejected casting permanent mold right here we say you can see aluminum pistons so these are made by what say permanent molding and we can see here automotive engine blocks produced by gravity die casting so these are the engine blocks which are used in the automotive so these engine blocks are made by permanent molding process now let us see the advantages of gravity die casting better mechanical properties why the molten metal is being poured into the what say metallic molds then what will happen the cooling rate will be faster once the cooling rate is faster we get the mechanical properties like so better mechanical properties are obtained in the gravity die casting next one homogeneous grain structure and chemical composition can be obtained why because we exert pressure and because of this pressure the molten metal will be trapped between the two dies that is how we get the homogeneous grain structure and chemical composition next one again low shrinkage and gas porosity in the case of the conventional sand castings what will happen there is always a chance for the shrinkage cavities now here the shrinkage cavities cannot form more rarely they form why why there is no shrinkage cavity because we are exerting external pressure on the molten metal see if there is any shrinkage that will be nullified so that is the shrinkage cavity and also even if there is a gas porosity same thing can happen because we are applying external pressure this what say gas tiny gases that are present inside the mold will be inside the metal will be escaping so low shrinkage and gas porosity we get the final next we get the good surface quality why if we use the sand mold what will happen the what say mold surface will have a rough texture because how why how this what say sand mold is made it is made up of sand so because of the sand grains present on the surface the texture will be rough even finally even this rough texture will be transformed to the transferred to the casting that is how the surface roughness of a sand casting will be very poor but here we are not using a sand mold we are using a metallic mold metallic mold thus the inner surface what say will be having a very good fine surface finish then into such a mold when we pour the molten metal the casting will also have a very good surface quality next one low dimensions tolerances in the case of the sand casting because there is a rough surface on the casting so we need to machine so we give the machining allowance that is how there won't be any what say there will be lesser dimensional tolerance where is here in the case of the die casting already the mold what say metallic mold is very smooth so minimum machining will be done sometimes no machining then what will happen there will be closer dimensional tolerance there will be very good dimensional accuracy so these are the advantages of gravity die casting next one we will see the limitations of gravity die casting one is the costly mold making this mold is not that much easy not that much cheap if it is a sand mold within 1 hour 1 can make and say the cost involved may not be very high but here the material is costly we use special alloys so that way the material is costly and making is not that much easy sometimes the what say that alloy will be tough to machine we need to use what say advanced machining process in which case the machining would be expensive machining would be difficult and it will be laborious and it will be time consuming so that is how the cost of making the mold will be going up so that is how we can conclude that it is a costly mold next one only for components of simple shapes complex shapes cannot be obtained using gravity die casting or the permanent molding process next one we have completed the gravity die casting next one we will see the pressure die casting again the pressure die casting is subclass fed as cold chamber pressure die casting second one is the hot chamber pressure die casting first we will see the cold chamber pressure die casting pressure die casting is believed to have begun sometime during the middle of the 19th century it is not very old it is only what say 100 years old about 100 years old according to the records Sturges patented the first manually operated pressure die casting machine during 1849 so this man has patented the pressure die casting various compositions of tin and lead were the first die casting alloys initially pressure die casting was meant for casting tin and lead components their importance and use declined with the development of zinc alloys later zinc alloys were developed so slowly people started even making zinc castings using pressure die casting process next to finally magnesium and copper alloys were used using the they were cast using the pressure die casting process. Now pressure die casting again is subclass fed into two types one is the cold chamber pressure die casting and the second one is the hot chamber pressure die casting in the case of the cold chamber pressure die casting the furnace which is meant for melting metal is away from the this machine it is not an integral part of the machine where is in the case of the hot chamber pressure die casting machine the furnace which is meant for melting the metal is an integral part of the machine. So that way these two are different first we will see cold chamber pressure die casting process. Now, this is the schematic diagram of cold chamber pressure die casting process. What is there here? Here we can see this is the again there will be metallic moulds will be there, die means metallic mould. So, here this is the fixed die and this is the movable die and each die has a cavity both the fixed die and the movable dies they have cavities engraved inside. So, when we close these rays together inside there will be a cavity here we can see there is a cavity. So, this is the shape of the casting which we want now these are the ejector pins and this is the cavity. Now, this is the short chamber it is a cylindrical short chamber now the here we pour the molten metal molten metal and here we can see this is the ram after the molten metal is poured into the short chamber the ram will exert pressure external pressure on the molten metal and the molten metal will be squeezed inside the cavity because of the external pressure that we apply the molten metal will be squeezed and it will be going inside the cavity like this there it solidifies. So, this is the simple principle of cold chamber pressure die casting process and here we can see the animation of the cold chamber pressure die casting process and here we can see this is one die this is the fixed die and this is the movable die you here we can see this is the cylindrical chamber in which molten metal is being poured and this is the ram or the piston it is exerting pressure inside the die inside these two dies then there it solidifies and the casting will be taken out yes here we can see yes this is the casting again it will be poured again it exerts pressure between into the die and casting solidifies and the casting will be taken out. Now here we can see a cold chamber pressure die casting machine another cold chamber pressure die casting machine we can see here and these are the dies we can see here now let us see the advantages of cold chamber die casting process simple construction thus cost of the equipment is not very high what is there two metallic molds are there and yes there will be ejector pins will be there and a cylindrical chamber is there and a piston or a ram and we just pour the molten metal and push it so it is a simple construction then what are the disadvantages of cold chamber die casting process slower cycle time due to the need to transfer the molten metal from the furnace to the cold chamber machine what is this sometime back I told you in the case of the cold chamber die casting process the furnace will be away from this machine it is not a it is not an integral part of this machine then what will happen every time we have to go to that furnace tap some molten metal carry it in a ladle then bring it to the cold chamber die casting machine pour it then push it in this process what is happening there is a time delay every time we have to go to the furnace carry some molten metal then you pour that is how it is the slow years like cyclic time due to the need to transfer the molten metal hence the rate of production will be less naturally so that is the disadvantage of cold chamber die casting process now let us see the alloys cast with cold chamber die casting process A360, A380, A383, A384, A390, A413 and A518 so these are the alloys which are cast using the cold chamber die casting process next one what are the alloys in among the zinc alloys what are those alloys let us see among the zinc Z812, Z827 are the zinc alloys which are cast using the cold chamber die casting process coming to the magnesium alloys among the magnesium alloys AZ91D, AM60A, AS4S41A so these are the magnesium alloys which are cast using cold chamber die casting process coming to the copper alloys of course coming to the copper alloys most of the copper alloys can be used can be cast using the cold chamber die casting process now these are the applications of cold chamber die casting process this process is used to make automotive components you can see here this is an automotive what is a component so this is made up of cold chamber die casting process next one it is used for making electrical motor frames and housings and here we can see this is a electric motor housing so this is made by cold chamber die casting process next one complex shapes and thin walls here we can see there are complex shapes and also thin walls so this component is also made by cold chamber die casting process next one we will see hot chamber pressure die casting process so first of all before going again it has got two subclassifications before going to subclassifications we must be what say again I must remind you that hot chamber pressure die casting means the furnace for melting the molten metal is an integral part of that machine again it is subclassified as gooseneck air injection type and the second one is submerged plunger type so first we will see the gooseneck air injection type hot chamber pressure die casting machine now here again as usual what is the what is a hot chamber pressure die casting process the furnace meant for melting the metal is an integral part of the machine see this is that machine hot chamber what is a pressure die casting machine and here we can see this is the furnace so you can see here the here is the molten metal and initially the metallic blocks will be kept inside this furnace in this what is a metal part then here there is a fire box using this fire box there will be coke or oil it will be burned and because of that the molten blocks will be melted and there will be molten metal will be there so here we can see that the what is a furnace is an integral part of the machine next we can see here there is a gooseneck what is a cylindrical chamber is there gooseneck chamber is there now the molten metal will be entering into this cylindrical what is a cylinder from this part it enters then what will happen air will be coming and air exerts pressure on the molten metal the molten metal will be slowly it will be transferred it will be transferred in fact it will be pushed and it will be coming up to here you can see and here we can see this is the stationary die and this is the movable die of course we can see ejector pins are also there so this is the gooseneck injector so the initially the molten metal from the metal part will be transferred to the gooseneck injector and because of the air because of the pressure exerted by the air the molten metal will be injected into the what is a cavity between the two dies what will happen then it solidifies between the molten metal solidifies between the two dies and there will be a cooling system because of the cooling system the molten metal quickly solidifies and after cooling is over the this is the movable die and because of the ejector pins it comes out and the casting will be taken out again it will be closing same thing will happen again the molten metal from the metal part enters into the gooseneck injector the air will come and because of the pressure of the air the molten metal will be injected into the cavity between the two dies so this process goes on and no need to carry the molten metal from a far away place then you pour it no such business is not there that is how the rate of production will be faster in the case of the hot chamber pressure die casting process and now let us go to the second type that is the plunger type hot chamber pressure die casting process in the case of the gooseneck air injection so we are sending what is a pressurized air to inject the molten metal into the metallic dies now there is sometimes there is a risk that this air contains oxygen and this oxygen may react with the molten metal and causes oxidation that is why people have also developed the another type that is the plunger type so here no air injection will be there there is no air instead of air there will be a plunger will be there now how to study this so this is the again we must know that hot chamber pressure die casting means the furnace meant for preparing making the molten metal is an integral part of the machine now this is that furnace here we can see this is that furnace so this is that what is a furnace part right so this is the furnace and here we can see this is the refractory what is a lining will be there so that it can withstand very high temperature now this is the part this is the part inside that part we place the metallic what is a blocks initially now there will be heating system will be there and because of that heating system the metallic blocks will be melting and there will be molten metal will be there now how to study the next parts so here there is a hydraulic short cylinder is there so this comes down and goes up hydraulically it can exact very high pressure now you can see here the molten metal enters into the here there is a cylindrical what is a chamber is there cylindrical chamber the molten metal enters into the cylindrical chamber once it enters into the cylindrical chamber here we can see the gooseneck what is a plunger will be coming down because of the hydraulic what is a pressure once it comes down what will happen the molten metal is trapped between the plunger and the dies then what will happen the molten metal will be injected at a very high pressure yet it will be injected between the cavity of the two dies and here we can see there are two dies here is this is the fixed die and this is the movable die and between the fixed die and the movable die there is a cavity is there you can see right so this is the this is also known as the ejector die movable die is also known as the ejector die here the there is a cavity now once the what is a gooseneck plunger what is a push is pushed down the molten metal is trapped and it will be injected into the cavity here once the molten metal fills that cavity yes there will be cooling system will be there so this cooling system what is a flows around the what is a molten metal and the molten metal inside the dies will be solidifying at a very fast rate then what will happen the movable die will be moving this side to the left side then the casting will be ejected again it will be closing the same thing again the molten metal will be entering into this what is a cylindrical chamber again the plunger will be coming down the molten metal will be injected into the cavity of the dies so this process keeps on going now what is the benefit here benefit is the chamber is an integral part of the machine so no need to carry the molten metal from a far away place and then you pour no there is no such business automatically the molten metal will be entering into the what is a this see cylindrical see once the casting is taken out immediately closes the molten metal enters into that cylindrical chamber it will be pushed the what is a plunger will be coming down and it will be injected so the benefit the rate of production will be very fast what is the speed you can see here 902 18000 shots per hour in 1 hour we can produce 902 18000 castings we can produce what a great speed it is if it is the sand casting in 1 hour we can produce 1 casting but here in 1 hour we can produce 902 18000 castings so that is the great benefit of hot chamber pressure day casting process here we can see the animation so this is the what say what say this is the furnace and here we can see the molten metal is going inside and here we can see the goose neck plunger is coming down and these two are the dies the molten metal will be injected inside immediately there will be a cooling system to cool the what say casting and it will be ejected and the casting will be taken out so this is the what say animation of the hot chamber pressure day casting process and here we can see another hot chamber day casting machine and here we can see 8 ton hot chamber day casting machine this is the largest hot chamber machine in the world and it costs about 1.25 million dollars you can see the height its height its height is double than the height of an average man you can see here maybe it must be the height must be 12 feet and this is the length so this is the world's largest hot chamber day casting machine these are the typical day casting modes so these are the dies dies means metallic modes which are used in the what say hot chamber day casting process when we close this we can see here these are the what say this is the male day and this is the female day the male day has got some pins are there four pins and here there are four holes are there when we close so these four pins will be going inside the four holes and there will be cavity between these two dies again these are the metallic modes which are used in the what say hot chamber pressure day casting process metallic modes nothing but these are the dies dies means metallic modes when we close these two say there is a cavity so these are the dies now allies cast with hot chamber day casting process zinc allies can be cast tin allies can be cast lead allies can be cast and finally magnesium allies also can be cast using hot chamber day casting process and what are those among the zinc allies 3, 5, 7 so these are the jamak zinc allies so these can be cast using hot chamber day casting process and also GA8 alloy can be cast using the hot chamber die casting process. Next one important applications of pressure die casting process, carburetor bodies. These carburetor bodies are very important components in the automotive especially in the petrol what say vehicles, this carburetor what say mix is petrol and air uniformly. So this carburetor body is made up of what say pressure die casting. Next one hydraulic brake cylinders these are made up of pressure die casting. Connecting rods and automotive pistons, oil pump bodies, aircraft components, sports goods, household utensils, plumbing goods all these in fact these are some examples. In fact many more components can be made using pressure die casting and here we can see important applications carburetor bodies produced by hot chamber die casting process. So these are the carburetor bodies used in the automotives. This is another component thin component produced by hot chamber die casting process. So again this is a what say cast product of hot chamber die casting process. Next one automotive components produced by hot chamber die casting process. Here we can see these are the automotive components, these are produced by hot chamber die casting process. Next one, this is another component produced by hot chamber die casting process. Next one, we can see here this is the trimmed brake drum, so this is made by pressure die casting process. This is the male die of a center gated brake drum, this is the male die. Now we can see here more examples, so all these components are made by pressure die casting process. So these are the zinc die cast parts, you can see excellent surface finish is there. So these cast parts are made by hot chamber pressure die casting process. So this is a belt roll, it is a zinc what is a casting, it is made up of what is a pressure die casting process. Now let us see the advantages of hot chamber die casting process, closer dimensional tolerance, what is the tolerance? 0.002 mm, excellent dimensional tolerance can be obtained using hot chamber die casting process, excellent surface finish on the castings. You can see here 1 to 2.5 microns, very good surface finish can be obtained, very thin sections as thin as 0.75 mm can be easily obtained using hot chamber die casting process. Next one, components of different sizes as small as 30 grams and as big as 7 kgs also can be successfully cast, useful for mass production, mass means same components produced one after another continuously that is the mass production. One set of die can produce about 10,000 castings, if we make one what is a set of metallic moulds. So this set of metallic moulds will serve us for making, producing 10,000 castings. So this is the greatest advantage of hot chamber die casting process. Next one, cycle of operation requires less time, very very less time is consumed in a cycle, faster rate of production, shrinkage and gas porosities can be avoided, why? Because we are exerting pressure, so because of that pressure if there is any shrinkage it will be nullified, if there is any gas porosity it will be nullified. Next one, semi-skilled workers can do the job, why? Because in the case of the sand casting process the pattern has to be withdrawn, if it is not done by a skilled person the mould will break and so many things, but here there is no such thing, even a semi-skilled worker can do the job, less defects compared to the sand casting. Casting surface is free from sand particles, so no need to wash, less floor space is required. In the case of the sand casting process there will be a pattern shop will be there for making the pattern, there will be a moulding shop for making the sand and there will be moulding shop, there will be melting shop, there will be fettling shop, there will be what is a machining shop likewise, so many shops will be there and what is a sand, what is a casting industry requires large space, whereas in the case of the hot chamber die casting very less floor space is required, these are the limitations of hot chamber die casting, cost of the equipment is very high, even cost of the die is very high, why? The material we use for the die is expensive, sometimes it is very hard, machining it is a tough task, it requires advanced machines, that is how the cost of the die is high not suitable for heavy castings, only small casting and medium sized castings can be made using hot chamber die casting process, suitable only for non ferrous castings you see very important limitation of hot chamber die casting process, only aluminum, copper, magnesium zinc and lead alloys can be cast, what about the ferrous alloys cast iron steel, no they cannot be cast using hot chamber die casting process, not suitable for small scale production why? Making the die is what is a time taking process, it is a laborious process and it would become very expensive, after making a set of dies if you make only two three castings then you discard those dies, then it is not what is a useful, so not suitable for small scale production, oxidation of melt in the air injection machine, so this can happen in the glue snake in air injection type, because we send the pressurized air, so oxygen in the air may react with the molten metal, but of course this may not takes place in the case of the plunger type, diffusion of iron and hard elements into the cast melt plunger type machine, now the second type is the plunger type what is a hot chamber die casting process, in this process what we are doing there will be a plunger, this plunger will be pushing the molten metal into the dies, now this plunger is made up of a special steel, so it contains certain hard elements like tungsten molybdenum, then what will happen, when it comes in contact with the molten metal and it is pushing the molten metal inside, the hard elements like tungsten or molybdenum may come out of the plunger, they may mix with the molten metal and they those elements may go inside the what is a cast component, and that will be the case the property of the casting will be altering, so diffusion of iron and hard elements may take place in the case of the plunger type machines. Now alloys cast with cold chamber die casting process, in detail we are seeing aluminum alloys A360, A380, A383, A384, A390, A413, A518, coming to the zinc alloys Z812, Z827, coming to the magnesium alloys AZ91D, AM60A, AS41A and some copper alloys. Now aluminum alloys used in cold chamber die casting machine, so we are going to learn few more details about these alloys, A380 aluminum alloy is most commonly used because it offers the best combination of casting and product properties, it is used for the widest variety of products, electronic stresses, engine components, home appliances, hand and power tools and so on. So these are the what is a applications of A380, what is a aluminum alloy. Next one A383 and A384 are the alternatives to A380, used for intricate components with improved dry filling characteristics and improved resistance to hot cracking. Next one A390 alloy offers the greatest wear resistance, it has a very high silicon constituent used for making engine blocks, once there is a silicon what is a component, once there is a high silicon proportion is there what happens, it enhances the fluidity and also it induces the wear resistance to the cast product. Next one A360 alloy offers improved corrosion resistance and superior strength at elevated temperatures compared to A380 alloy, both copper and zinc are reduced in this alloy compared to A380 alloy. Next one A413 alloy offers excellent pressure tightness, its silicon constituent is near the eutectic composition, it has excellent fluidity and useful for intricate details. Here the silicon constituent is at the eutectic composition means what, eutectic composition has the lowest melting point. So because of the lowest melting point, it offers higher fluidity. Next one A518 alloy has very good corrosion resistance and ductility, it is used in marine and aircraft hardware and also in escalators. Next one we will see details of zinc alloys used in hot chamber die casting, ZA alloys. ZA12 with 11 percent aluminum and 1 percent copper typically has properties between ZA8 and ZA27. ZA27 with 27 percent aluminum and 2.2 percent copper has the highest melting point and highest strength and lowest density of these three alloys. Next one both ZA12 and ZA27 are used for cold chamber die cast because of their elevated melting points and aluminum contents. Next one details of magnesium alloys used in the die casting, AZ91D is the most what is a useful alloy among the magnesium group. It is found in several automotive components as well as hand held and laptop computers. AM60A is an alloy with aluminum and magnesium, it has good ductility and toughness, ability to absorb energy before pairing. It is used in automotive wheels and steering wheels and archery equipment. Yes 41A is the alloy with aluminum and silicon, it has creep strength at elevated temperatures. These properties made it a choice for air cooled automotive crank cases. Next one alloys cast with hot chamber die casting process. In detail we are going to see among the zinc alloys 3, 5, 7, jammer alloys and ZA8 alloys. Jammer alloys this three zinc jammer alloys is the work horse alloy of this group means it is widely used. It is the it is specified most frequently for functional and hardware castings. Next one 5 jammer alloys has higher tensile strength, hardness and creep resistance. It also has somewhat lower ductility. This is due to the increased copper content. A common application is automotive locks. Next one 7 jammer alloys is a high purity form of 3 jammer alloys. It has slightly lower hardness and higher ductility. It has higher fluidity than either 3 or 5 jammer alloys and could be a better choice for thinner walls and finer details. Next one ZA alloys ZA8 with 8.4 percent aluminum and 1 percent copper has the lowest melting point and highest density of the 3 alloys. It has the highest strength and highest creep strength of any zinc alloys. Next one we will see the alloy selection chart means which cast alloy to choose for a particular purpose. So these are all the requirements sometimes cast volume or sometimes small castings or medium to large castings, light weight, high strength to low density, high tensile yield strength sometimes surface finish may be an important criteria or missionability or process cost. So these are our criteria selection criteria and these are the 4 types of the alloys. These are the aluminum alloys, magnesium alloys, zinc alloys, jammer alloys and these are the zinc alloys. If it is the cast volume is important means we are bothered about the what say volume more volume is to be produced then that be the case aluminum alloys are to be chosen for our what say die casting purpose. Now small castings but with what say close dimensional accuracy and what say surface finish that be the case we can go for the zinc alloys. Medium to large castings then we can use aluminum and GA alloys, light weight that be the case magnesium is there, magnesium alloys can be used, high strength to low density is our requirement that be the case again magnesium can be used. Now next criteria high tensile yield strength that be the case we can use aluminum alloys we can also use GA alloys. Next one surface finish should be good that is our requirement that be the case we can go for magnesium alloys GA alloys. Next missionability should be good that be the case we can use magnesium alloys. Next one process cost that be the case we can go for the zinc alloys. Next one die casting characteristics of alloys. Now here we can see these are the what say characteristics resistant to hot cracking, die filling capacity, anti-soldering to the die, corrosion resistance, machining yeast, electroplating yeast, strength at elevated temperature and these are the different alloys A360, A360.0, A360, 360.0, this is 360 right, 380, 380.0, A380, A380.0, 383, 383.0, 384, 384.0, 390, B390.0. Now one means most desirable for that characteristic, five means least desirable. We can see here for resistant to hot cracking, we can see yes 360 and 360.0 is least desirable. Similarly, A360, A360, A360.0 is also least desirable, A380, 380.0 we can see it is close to least desirable, same is the case with the A380 and A380.0, 383 and 383.0 again is least desirable, what is good 390 or B390.0 is close to most desirable. Next one, die filling capacity, when this is the characteristic now what say A360 and 360.0 is in the middle, again A360 and A360.0 is also in the middle, A380 and A380 alloys are close to most desirable, whereas 383, 384 alloys are most desirable, these are most desirable. Next one, 390, B390 is also most desirable, next anti-shouldering to the die, that be the case say these two alloys, 360 alloys, A360 and A360 alloys are close to most desirable whereas 380 and 380 alloys are most desirable. Next one, 383, 384 and 390, these alloys are close to most desirable, coming to the corrosion resistance characteristic, 360 and A360 are close to most desirable, whereas A380 alloys are close to least desirable and A380 is in the middle, 383 is in the middle, next one 384 is least desirable and 390 is in the middle. Next one, machining is we can see here all these three alloys are in the middle, whereas 383 is close to most desirable, again 384 is in the middle and 390 and B390 are most desirable. Electroplating is coming to that these two alloys, 360 and A360 are close to most desirable and these three, 380, A380 and 383 are most desirable alloys, whereas 384 is close to most desirable and 390 is in the middle, coming to the strength at elevated temperature, 360 and A360 are most desirable, whereas 380 and 380 are in the middle, next one 383 and 384 alloys are close to most desirable, again 390 is in the middle. Next one, coming to the few more alloys are there, 13, 413, A13, A413.0, 43, C443.0, 218 and 580.0, coming to these restraints to hot cracking, this alloy is most desirable, whereas 218 and 518 is least desirable. Tie filling capacity, these two alloys are most desirable, this is close to least desirable and this is most least desirable, anti-shorting to the die, these two alloys are most desirable and this one is least desirable. Corrosion restraints, these three are close to most desirable and this is most desirable. Next one, machining is these two are close to least desirable, this is least desirable and this is most desirable. Coming to the electroplating is these two are in the middle, this is close to most desirable and this is least desirable. Coming to the strength at elevated temperatures, these two alloys are in the middle, this alloy is least desirable and this alloy that is the 218 or 518.0, these two alloys are close to least desirable alloys. Friends, in this lecture we have seen the important classification of the die casting process. We have seen that die casting process means we use the dies, dies means they are the metallic molds. So, these metallic molds will be used for making thousands and thousands of casting. We have seen that broadly they can be classified into two types. One is the pressure die casting process and the second one is the what say one is the gravity die casting and the second one is the pressure die casting process. The gravity die casting is also known as the permanent molding process. Coming to the pressure die casting process there are two types. One is the cold chamber pressure die casting process and the second one is the hot chamber pressure die casting process. So, in the next lecture we will continue this die casting process. Until then, thank you and goodbye.