Study on grain refinement of copper-based liner by vacuum gradient heat treatment process using response surface methodology

Copper and copper alloys are some of the most studied and widely used liner materials. In this study, we investigated different heat treatment parameters on the tensile strength and grain size of copper alloys, and our experimental methods utilized a combination of central composite design (CCD) and response surface methodology (RSM). The material was subjected to vacuum gradient heat treatment under the optimized heat treatment parameters, and the material microstructure after the heat treatment was assessed using electron backscatter diffraction (EBSD) analysis. Studies have shown that an increase in heating temperature and holding time results in grain coarsening and lower tensile strength values. As a result, the optimized heat treatment process allowed the material to undergo incomplete recrystallization. Furthermore, additional grain refinement and a reduction in texture strength and dislocation density improved the performance of the liner.