热处理对5083铝合金晶间腐蚀与力学性能的影响

Influence of heat treatment on intergranular corrosion and mechanical property of 5083 aluminum alloy

采用光学显微镜、扫描电镜、硬度试验机和电子万用试验机等研究了合金的显微组织、晶间腐蚀情况和力学性能。结果表明,经过稳定化处理后的试样析出了不连续的第二相,稳定化处理和冷轧后的试样均无晶间腐蚀现象,试样在180℃下退火后,试样内形成了等轴晶粒,晶界上连续分布的β相,出现了晶间腐蚀现象,保温90h比15h晶界上析出β相更多,试样的晶间腐蚀更加明显;合金稳定化处理后硬度最高,冷轧后试样的硬度最低,在180℃下退火保温15和90h的硬度比冷轧后高,但低于稳定化处理后的试样,稳定化处理和退火后的试样的塑性较冷轧态好。

The microstructure,intergranular corrosion phenomenon and mechanical property were investigated by means of metallographical microscope,SEM, hardness tester, mechanical property testing machine. The result showed, discontinuous phase precipitated after stabilization heat treatmenting,and the phase was scarcity, there was no intergranular corrosion phenomenon when the samples cold rolled and stabilization heat treatmented. Equiaxed grains appeared after annealing, continuous phase precipitated at the grain boundaries, the intergranu- lar corrosion was happened,but the intergranular corrosion was more obviously annealed for 90h than for 15h; the hardness of 5083 aluminum alloy reached highest when it was stabilization heat treatmented,it was lowest when cold rolled, the hardness of the samples annealed was lower than stabilization heat treatmented, but higher than cold rolled. The alloys plasticity after stabilization heat treatmenting or annealing was better than after cold rolling.