Influence of sampling method on performance evaluation results of aviation aluminum alloy forgings

The bottom of 7055 aluminum alloy aviation wheel hub tire die forging blank was sampled by three methods of different directions, different positions and different specifications, and the mechanical properties of the samples were tested. The effects of different sampling methods on the test results and their effects on the performance evaluation of forgings were compared and analyzed. The results show that the larger the angle between the sampling direction and the forging streamline, the smaller the elongation after fracture. If the sampling position was very close to the surface of the forging billet, the surface defects would obviously reduce the strength and elongation of the sample. When the sampling position was in the deformation zone with good streamline, the test results were larger. When the sampling position was in the geometric center, the test results could truly reflect the service performance of the forging. When the sampling position was on the defective surface and the non－geometric center with good forging streamline, the service performance of the forging could be truly reflected. In a certain area, the tensile sample specification did not affect the test results, and when the length of the tensile specimen passed through the streamline junction area, the test results were abnormal. The results obtained by improper sampling methods couldn′t be used to correctly evaluate the mechanical properties of the forged wheel hub.