搅拌摩擦加工细晶AZ91镁合金的加工特性（英文）

Machining characteristics of fine grained AZ91 Mg alloy processed by friction stir processing

搅拌摩擦加工细化AZ91镁合金,研究钻孔过程中不同切割速度和进料速率下晶粒尺寸和二次相对加工特性的影响。经搅拌摩擦加工得到了过饱和AZ91镁合金,晶粒尺寸由(166.5±8.7)μm细化到(21.7±13.5)μm。相比未加工的AZ91镁合金(HV(108.2±15.6)),经搅拌摩擦加工的合金硬度为HV(88.95±6.1),这归因于二次相的减少。然而,搅拌摩擦加工AZ91合金的平均切割力略微减小。相比未加工的AZ91镁合金,搅拌摩擦加工AZ91合金的钻孔边缘损伤较低。因此,虽然在钻孔过程中晶粒细化可以略微增大切割力,但在AZ91镁合金加工过程中边缘处理较好。

AZ91Mg alloy was considered and friction stir processing(FSP)was adopted to achieve grain refinement to investigatethe effect of grain size and secondary phase on machining characteristics during drilling at various speeds and feeds.Super saturatedAZ91Mg alloy was obtained after FSP and the grain refinement was achieved from(166.5±8.7)μm to(21.7±13.5)μm.Surprisingly,hardness reduced for FSP AZ91Mg alloy(88.95±6.1)compared with AZ91alloy(108.2±15.6),which was attributed to the reducedsecondary phase.However,the mean cutting force for FSP-treated(FSPed)AZ91Mg alloy was marginally increased.The edgedamage of the drilled holes was lower for FSPed AZ91Mg alloy compared with unprocessed AZ91Mg alloy.Hence,it can beunderstood that the grain refinement may slightly increase the cutting forces during drilling but better edge finishing can be achievedin machining of AZ91Mg alloy.