Test of shrinkage porosity mechanical properties of semi solid die casting thick wall products

Vickers hardness measurement

The unit of hardness measured is micro Vickers hardness. When hv-30 Vickers hardness tester is used, the diamond indenter will slowly drop to the surface to be measured, and the set force will be applied. The holding time of the force is 10s. After the force is applied, the length of two diagonal lines is recorded, and the average value is calculated. Finally, the Vickers hardness at this point is obtained by looking up the table Degree value. In the test, 35 hardness tests are carried out for each position, and the average value and variance are taken as the hardness value and error value of the point.

Room temperature tensile properties

Tensile property is an important research object and index in this project. Because of the need to compare the tensile properties at different heights and different radial positions. Therefore, it is necessary to prepare rod-shaped tensile specimens at different heights of the samples and to prepare sheet tensile specimens on the same cross-section. The tensile properties test results include tensile strength, yield strength and elongation. Fig. 2 is the schematic diagram of rod-shaped tensile specimens made at different heights in this test, and Fig. 3 is the schematic diagram of sheet tensile specimens made along the diameter direction at the same height in this test.