连续挤压Al-1.1Mg-0.3Cu合金的拉伸性能和加工硬化行为

为了提高Al-1.1Mg-0.3Cu合金线杆的拉伸性能,通过金相、透射电镜、扫描电镜显微组织观察和拉伸试验分别对连续挤压态及拉拔退火态合金的微观组织和拉伸性能进行了研究.结果表明:连续挤压成形工艺有助于进一步改善合金的拉伸性能,与传统拉拔后退火处理工艺相比,通过连续挤压工艺制备的合金组织晶粒细小而均匀,沉淀相和位错密度较少,致使合金的延伸率相对较高而加工硬化率相对较低;此外,相比传统工艺,由连续挤压工艺制备的合金拉伸试样断口形貌中韧窝更深、更细小.

Tensile Properties and Work Hardening Behavior of Continuous-extruded Al-1.1Mg-0.3Cu Alloy

In order to improve the drawability of Al-1.1Mg-0.3Cu alloy wire rod, the microstructures and mechanical properties of continuous extruded and conventional drawn and annealed alloys were investigated by observation of optical microscopy, transmission electron microscopy and scanning electron microscopy and tensile testing. The experimental results show that continuous extrusion forming produced a finer, more uniform structure, with fewer precipitates and lower dislocation density, than that resulting from conventional drawing followed by annealing processing. Increased tensile elongation, lowered work hardening rate, and enhanced drawability resulted from continuous extrusion processing. The fracture surface of the material prepared by continuous extrusion presented deeper and finer dimples, compared with that of the conventionally processed material.