退火温度对TU2无氧铜力学性能及磨损性能的影响规律OA

In this study,the effects of different annealing temperatures(200,250,300 and 350℃)on the microstructure,mechanical properties and friction and wear properties of TU2 oxygen-free copper were analyzed using OM,SEM/EDS,3D/CLM,tensile testing machine,and friction and wear testing machine.The results show that with an increase in annealing temperature,the grain sizes of copper alloy gradually increased,and the number of annealing twins increased;the wear resistance exhibited a trend of increasing first and then decreasing.TU2 oxygen-free copper exhibited the highest yield strength(295.3 MPa),tensile strength(303 MPa),and the Vickers hardness(94.7 HV)at an annealing temperature of 200℃,demonstrating a superior balance between strength and plasticity.This was primarily attributed to the inhibition of dislocation movement by fine-grain strengthening,dislocation strengthening,and the presence of annealing twin boundaries.Regarding wear resistance,the sample annealed at 250℃exhibited the best wear resistance,with a wear volume of only 30.73×10-3 mm3/(N·m),attributed to the retention of an appropriately work-hardened microstructure.Although a stable oxide film formed on the surface of the sample annealed at 350℃(reducing the coefficient of friction to 0.414),its wear volume increased significantly compared to the 250℃annealed sample.This degradation in performance was mainly due to the insufficient load-bearing capacity of the matrix,which weakened its resistance to ploughing and plastic deformation.