Mechanical Testing is a very important part of the manufacturing process. Ensuring the safety of tested products is the primary goal of all mechanical testing.
Types of testing
There are a large number of tests involved in the testing process to determine the various mechanical properties of the materials involved. Here at Code A Weld, we are going to discuss some of the following tests that are involved.
Hardness tests are used in Mechanical Engineering to determine hardness (or resistance) of a material to deformation. These hardness tests can be divided into three classes: macro, micro and nanoindentation.
Three types of Hardness testing:
- Macroindentation tests are for tests with a larger test load (1kgf or more).
- Microindentation tests are for tests with a lower test load (1 – 1000gf).
- Nanoindentation tests are applied to small volumes.
Tensile Testing is used to determine the stress-strain curve for a material and subsequently other values such as Youngs’ Modulus, yield stress, tensile stress and % elongation to failure. All of this is to ensure that the material meets minimum strength and ductility requirements.
Fracture Toughness testing
Fracture Toughness is the critical stress intensity factor of a sharp crack where propagation of the crack suddenly becomes rapid and unlimited. The testing provides information about a materials capability to withstand flaws and the effectiveness of its strength.
Creep Testing is used to determine the mechanical properties of materials at high temperatures. These tests provide critical information to engineers, enabling them to prevent failures by giving them insights into the long-term stress on materials and products.
Fatigue Testing is performed by applying cyclic loading to a structure. These tests are used to generate fatigue life and crack growth data, identify critical weak points and demonstrate the safety of a structure that may be susceptible to fatigue. From the data, a fatigue strength curve is established and then the results from that are compared to the design criteria in order to ensure that the material will enable the component to fulfill its projected life expectancy.
Nondestructive Testing (NDT) is named as such because it does not cause permanent damage to the article being inspected. Therefore, it is highly valuable because it can save both money and time. NDT employs the use of electromagnetic radiation, sound and other signal conversions to examine a wide variety of articles.