Strength determination of small components:
Thin-walled tubes, layers, thread flanks, razor blades
Testing the strength of small parts with low load level
The strength testing of small components often presents a challenge in materials testing. Usually, micro-tensile tests are carried out, which are very time-consuming and costly due to the sampling and preparation of samples. In some cases it is not possible to take a micro tensile specimen.
With the indentation method according to DIN SPEC 4864 it is possible to determine the 0.2% proof stress and the tensile strength of small components or test points with small dimensions quickly and with little destruction. Testable are metallic materials such as steel, aluminium, titanium and nickel. With a test load of 5 kg, impressions with a diameter of approx. 0.4 to 1.2 mm can be achieved, depending on the material. The penetration depths are between 10 and 100 µm, so that even thin sheets can be tested.
Correspondence of the indentation method with the tensile test using the example of steel and aluminium
When testing with a load step of 5kg, the following relative deviations from the tensile test characteristics can be determined. The values are average values:
- Steel alloys
- Rp0.2: 7.7%
- Rm: 2.9%
- Aluminum alloys
- Rp0.2: 5.8%
- Rm: 6.4%
The mean value of five measurements with the indentation process was compared with the result of a tensile test. One point in the diagram corresponds to the result of the indentation method (x-axis) and the tensile test