激光选区熔化成形ZrH2/6060铝合金的显微组织与力学性能

Microstructures and mechanical properties of ZrH2/6060 aluminum alloy fabricated by selective laser melting

在6060铝合金雾化粉末中加入1%(质量分数,下同)的亚微米级ZrH2粉末,经过低能球磨制备1%ZrH2/AA6060复合粉,然后采用SLM(selective laser melting,激光选区熔化)成形工艺制备含锆的6060铝合金,表征和测试不同SLM工艺条件下合金的显微组织与力学性能,研究添加ZrH2对6060铝合金显微组织与力学性能的影响。结果表明:添加1%亚微米级ZrH2后,6060铝合金的致密度由93.8%提高至97.8%,成形试样开裂得到抑制,表面球化现象减弱,表面质量显著提高,表面平整,未出现较大孔洞等缺陷;材料的晶粒显著细化,尺寸由56μm减小至3μm。与6060铝合金相比,含锆铝合金的抗拉强度、屈服强度、伸长率、显微硬度分别提高26.0%,73.0%,126.8%和21.8%。

The 6060+1%ZrH2 composite powder was prepared by short-time low energy ball milling with 1%(mass fraction ,the same as below) submicron ZrH2 powder added into 6060 aluminum alloy atomized powder. Then 6060 aluminium alloy containing zirconium was prepared by Selective laser melting (SLM) forming process. The microstructures and mechanical properties of 6060 aluminium alloy were analyzed and tested with different SLM process conditions. The effects of ZrH2 addition on the microstructures and mechanical properties of 6060 aluminium alloy were studied. The results show that the density of 6060 aluminium alloy increases from 93.8% to 97.8% after adding 1% submicron ZrH2, and the cracking of formed sample is restrained. The surface spheroidization phenomenon is weakened, the surface quality is remarkably improved, the surface is smooth, and there are no large pores and other defects. The grain size of the formed sample is significantly refined from 56 μm to 3 μm. Compared with 6060 aluminum alloy without sub-micron addition of ZrH2, the tensile strength, yield strength, elongation and micro-hardness of AA6060+Zr specimens increase by 26.0%, 73.0%, 126.8% and 21.8% respectively.