Testing the mechanical properties of Metals reveal the elastic and inelastic behaviors of a material when a force is applied. We are able to determine if a Metal can withstand the common stresses for its intended purpose by measuring elasticity, tensile strength, elongation, hardness, fracture toughness, impact resistance, stress rupture and fatigue limit.
The most common testing is done with a Universal Testing Machine for testing the tensile properties of a Metal specimen (ASTM E8). Tension tests provide information on the strength and ductility of materials under uniaxial tensile stress until the point of fracture.
This system provides us with an excellent means of analyzing and predicting how a material will react under other types of forces. We are able to determine the ultimate tensile strength, maximum elongation and reduction in area from a simple tensile test. Knowing these measurements allows further calculations including Young's modulus, Poisson's ratio, yield strength and stain-hardening characteristics. A common tensile specimen is a cross-section of a sample with two shoulders and a gauge (reduced area) in between. The shoulders allow for easy gripping of the surface on a wedge grip for proper testing. Special milling machines can assist in the preparation of these tensile specimens according to ASTM E8, ASTM A370, etc. A Universal Testing Machine can also be configured for different testing procedures such as three point bending, four point bending, shearing, compression, etc. Contact us to further discuss how to configure a Universal machine to your specific application!
Hardness testing is the measure of how resistant a solid matter is to permanent shape change when an indenter is applied at a known force. When testing metals, the indentation hardness correlates linearly with the tensile strength of the material. The greater the hardness of the metal, the greater resistance it has to deformation. Depending on the application and the type of material, many scales are available to suit your requirements. Rockwell Hardness Testing scales (ASTM E18) uses the depth of penetration of a preload versus the depth of penetration of a major load by a diamond or ball shaped indenter. Brinell Hardness Testing (ASTM E10) is common for non-uniform type materials and uses the highest load and largest size ball type indenter. Vickers and Knoop hardness testing (ASTM E384) are performed using a diamond shaped indenter and are most commonly used for small parts, thin sections or case depth analysis. Contact us to further discuss which hardness testing method would be most suitable for you!
The area below a stress/strain curve produced from performing a tensile test is a basic measure of the toughness of the test specimen under slow loading conditions. Impact testing involves striking a specimen of known dimensions with a pendulum of a controlled weight and at a set speed. The measure of impact strength can assist in determining whether your metal is brittle or ductile. Impact testing is a very high strain-rate test which determines the amount of energy absorbed by a material during fracture. The energy absorbed after fracture is a measure of the materials notch toughness and assists in determining the properties of the metal. Based on the height of the pendulum before and after the procedure, the energy transferred to the material can then be inferred. Notching a sample is very important and has an effect on the results and must therefore be correctly prepared with specific dimensions and geometry. Charpy and Izod are two of the most common testing procedures and are commonly followed in the following industry standards: ASTM E23, ISO 148-1 and EN 10045-1. Contact us today to further discuss our impact testing equipment as well as our sample preparation machinery.
Further tests are available for the testing of Metals which will allow for further analysis of the mechanical properties. Some of these include Torque Testing, Fatigue Testing, Charpy Impact Testing, Bend Testing, Shear Testing, etc. Contact your NextGen representative today to further discuss how we can be your Quality Control solution.