Experimental study of short-term transient creep of the Al/SiC metal-matrix composite under uniaxial compression

The article presents the study results of the deformation behavior of a metal matrix composite (MMC) based on an aluminum alloy with 10 % SiC at temperatures ranging between 470 and 570 °C under a pressure of 4.8 MPa on the sample at the initial time (before deformation). The tests were performed in a pit furnace with the use of a specially designed and manufactured device. In the experiments, the samples are heated to a fixed temperature (470, 500, 530 and 570 °C) and held for a certain time, with a simultaneous exposure to a constant compressive axial load. The heating modes are given. The dependences of the degree of shear strain and the average strain rate on the holding time and temperature are obtained. A diagram of the pressure on the workpiece at the initial and final times for the temperatures under study is plotted. During the heating, starting from 530 °C, due to the deformation of the sample, the pressure decreases significantly and continues to decrease during holding; for example, after heating to 570 °C, it is about 40 % of the initial pressure value. It has been calculated that, during the heating period, the average strain rate does not exceed 0.00031/s. It has been found that, in the studied temperature range, the mechanisms of superplastic flow are likely to appear at the obtained values of strain rate and pressure on the workpiece. The results show that it is possible to create conditions of plastic deformation SiC of the Al/SiC MMC without fracture, with the degree of shear strain sufficient to manufacture blanks and complex shaped products in one manufacturing operation.