 Hello, I am Milka Jagle working as assistant professor in Department of Mechanical Engineering Walshian Institute of Technology, Solapur. Today, we are going to learn introduction to destructive and non-destructive testing methods. Let us see, learning outcome. At the end of this session, student will be able to select destructive, non-destructive material testing methods and its significance. So, this is the content for today's lecture, testing of materials, destructive testing methods that is DT, non-destructive testing methods and references. Testing of materials. What is the need of testing? So, what is the necessity of testing of material? So, think on this question. Let us see. So, materials are tested for the following purpose. First, to test the mechanical properties like tensile strength, brittleness, hardness, resilience and etc. To determine the data, the data for design purpose and analysis purpose. To determine surface and subsurface defects. So, there are various specimens in which defects are present. So, there are various methods to detect these surface and subsurface defects. Both destructive and non-destructive methods are used. To check the chemical composition of the metals and the compositions. To determine suitability of material for particular application. So, these are the points for which the material is tested. So, let us see what is destructive testing. As the name itself indicates, destructive test. It is the test in which the test specimen or the component is destroyed. As the slide indicates, in this test, the component or specimen either breaks or remains no longer useful for the further use. So, in this after test, we cannot use that specimen for the purpose. So, these are few tests. First is tensile test. In this test, the rod is held between two heads of UTM machine that is universal testing machine and the tensile load is given to it. So, the behavior of the rod after applying the load is observed. It is hardness test. Hardness test is nothing but indentation test. There are three tests in this, Brineal's hardness test, Rockwell's hardness test and Weaker's hardness test. It is impact test. In impact test, there are two tests are there, Izord and Charpie test. Fourth is script test and the fatigue test. So, we are going to see in detail in the further pipettes. In this type of testing, the rod or the specimen which is used is machine or it is of a cast bars. These tests indicates mechanical properties like tensile strength, ultimate strength, breaking stress and ductility, its roughness, hardness and these are all the properties through which we can get it. Tensile test is most commonly specified test. So it is performed on UTM that is universal testing machine. Tensile test is supplemented by hardness test. Hardness test gives information about wear resistance of material. There are three types of hardness test that is Rockwell's hardness, Brineal hardness and Weaker's hardness. Apart of this, Poldy's hardness test is also available. In impact test, both Izord and Charpie, so other mechanical tests are bend test and compression test which may be carried out along with tensile test on the UTM. So depending on the service condition, fatigue and creep test are also specified in some cases. So non-destructive test, the name itself indicates non-destructive. That is the specimen which we are going to use is not destroyed and it can be used for the further use. So in this test, the component or specimen does not break or even being tested, it can be used for the purpose for which it was made. So first is dye penetrant test. In this, the test specimen is clean and we are painting or we are applying the dye. So due to the capillary action, the defect is seen on that particle test is used to detect the defects in ferromagnetic materials. So in this, the specimen is magnetized and then ferromagnetic powder is applied or ferromagnetic is spread on the specimen. So the ferromagnetic powder cling at the defect area so that the defect is clear in the test. Then radiography that is x-ray and gamma ray. So this test is useful because in this, the subsurface defects are found out and in the ultrasonic test, so along with ultrasonic radiography and x-ray and gamma rays test is also there in which the subsurface defects are found out, eddy current test. So these are the tests which are used to detect the defects in the specimen without destroying the specimen. So as discussed before, NDT is an examination of component in any matter which will not affect its future use. Various tests are available for finding the internal soundness of components without sectioning or other destructive tests. The ability to detect invisible subsurface defects not only aids in maintaining high quality standards but provides valuable help to the development of manufacturing methods. So they do not provide direct mechanical properties but they are extremely useful in revealing defects in components that improves the performance when put in service. So NDT test, NDT test makes component more reliable and economical. So these are few types of non-destructive test. So I would like to revise destructive test. Destructive test is nothing but the test in which the component is destroyed and there are five types of test that is tensile test, hardness test, impact test. These are the test. So let us revise. There are five types of destructive test. So let us see. So these are five types of tensile test. That is these are five types of destructive test, tensile test, hardness test, impact test, creep test and fatigue test. And these are used for finding out the defects in the specimen. So in the same way we have non-destructive test. So these are non-destructive test, dipenetrant test, magnetic particle test, ultrasonic test, radiography test and eddy current test. These are the references, material science and metallurgy by Dr. Kodkire and introduction to engineering materials by B.K. Agarwal. Thank you.