【摘要】 在2000kN四柱液压机上对铸态、喷射态6061铝合金进行挤压处理,研究了挤压温度、挤压比对喷射态合金微观组织及力学性能的影响,分析了挤压态合金的断裂机理,并对比了铸态、喷射态合金挤压后的力学性能。结果表明,当挤压比为6.25时,随着挤压温度的升高,合金试样发生再结晶的晶粒数量增加,到250℃时形成均匀细小的等轴晶组织;合金的硬度和抗拉强度随挤压温度的升高而降低;但伸长率却随挤压温度的升高而升高。当挤压温度为250℃时,合金晶粒尺寸随挤压比的增大而减小;伸长率和抗拉强度随挤压比的增大而升高;而硬度受挤压比变化的影响则不大。挤压态合金的断裂机理为微孔聚集断裂。"喷射+挤压"态合金的抗拉强度和伸长率都比"铸造+挤压"态合金的高。更多还原

【Abstract】 Influence of extrusion temperature and extrusion ratio on the microstructure and mechanical properties of the spray-formed alloy which was extruded on 2000kN four column hydraulic press was investigated,and fracture mechanism of extruded alloy was analyzed,meanwhile,mechanical properties of as-cast and spray-formed alloy after extrusion were comparatively analyzed.The results reveal that at an extrusion ratio of 6.25,with increasing in temperature,number of recrystallized grain in the sample are increased to involve into fine and uniform equiaxed grain at 250℃,meanwhile,hardness and tensile strength of the alloy is decreased,while elongation is increased.At a temperature of 250℃,grain size in the alloy is refined,and elongation and tensile strength are increased with increasing in extrusion ratio,however,hardness of the alloy is almost independent of the change of extrusion ratio.Fracture of extruded alloy is characterized by micro-void coalescence mode.Tensile strength and elongation of the spray-formed and extruded alloy are obviously superior to those of as-cast and extruded ones.更多还原