Fundamental study on multi-layer friction surfacing of 2017 aluminum alloy on 6082 aluminum alloy

Abstract

This study investigates the multi-layer friction surfacing of AA2017 on AA6082, a solid-state process that enables the fabrication of alloys that are difficult to process using fusion-based methods. The research analyzes process characteristics, deposition efficiency, microstructure, and mechanical properties. The width of the deposited layers remained constant, while the thickness decreased with increasing stack height due to variations in heat transfer, leading to reduced deposition efficiency. Dynamic recrystallization transformed the typical rolled grain structure of the AA2017 T3 feedstock into fine equiaxed grains after deposition. Strengthening precipitates (rich in Mn, Si, Cu, and Mg) were observed within the grains and at grain boundaries. Tensile tests revealed an ultimate tensile strength (UTS) of 370¿±¿16 MPa and 80.6% UTS efficiency compared to AA2017 T3. Specimens near the substrate showed slightly lower UTS, indicating a subtle gradient along the stack. This work addresses a critical research gap by providing insights into the microstructural and mechanical behavior of AA2017 processed via friction surfacing.