Investigation of the friction weldability of an AlSi10MnMg-alloy reinforced with 30 Vol.-% silicon carbide particles with the adequate monolithic material

Due to their positive properties, AMC materials represent a current trend in industrial applications and thus a major research focus. But currently their difficult machinability limits a full establishment. Therefore, suitable joining processes are needed which allow a targeted and punctual use of the AMC-materials and thus minimize the machining effort. This paper presents a feasibility study of a direct material bond between an AlSi10MnMg-alloy reinforced to 30 Vol.-% with silicon carbide particles and the adequate monolithic material by using friction welding. For this purpose, in addition to the general feasibility, the achievable strengths are evaluated and the underlying material behavior as well as metallurgical processes are analyzed. As a result, the principle friction weldability of the used AMC material is demonstrated. Essentially, the joint results from a material bond between the aluminum alloy and the matrix material. The reinforcing phase contained in the latter remains unaffected by the joining process. The test results show neither transport nor mechanical comminution of the silicon carbide particles. It is proven that the quality of the produced material joint as well as the process stability depend on the setting of the variable process parameters. In particular, the ratio between frictional and forge pressure as well as the burn-off length are shown to have a major influence on the joint quality. The intensity of the individual influences is illustrated by the presentation of the parameter main and interaction effects as well as predominant significances. Because the used AMC material is softened by process- and material-related annealing effects, a large proportion of the weld specimens fail outside the joining zone. On the part of the unreinforced aluminum alloy, the absence of such temperature-induced softening is demonstrated. As a consequence, the investigated friction welding process can unusually not be aligned with the lower-strength material.