稀土La2O3粉末对激光增材制造多孔AZ61D合金的组织及性能影响目录.........................................................1......................................................2..................................................3..................................................3................................................3......................................3............................................4..................................................6....................................6..................................7......................................8....................................................8....................................................8..................................8............................................8............................................8........................................9.................................................10...............................................10...............................................11...............................................13.................................................14...........................................14.................................15...........................................15............................................................15.......16...17..........................................................19..................................................20...........................20.......................25.......28...........................................31.....................................................31.....................................................32....................................................33........................................................34摘要Mg合金是最轻的金属结构材料，比强度、比刚度高，有很强的抗辐射本领，可以广泛应用于航空航天、电子、和军事等领域，且有很好的发展空间。但是自身的加工和物理化学特性的制约，实际应用方面却很小，而且铸造Mg合金的气孔缺陷很多，组织晶粒粗大。选择性激光熔化技术的兴起有望推动Mg合金的应用，添加了稀土La2O3粉末后的合金性能也备受关注。本文以纯AZ61D粉末和添加了0.5%La2O3的AZ61D粉末为原料，利用选取激光熔化技术成形，利用扫描电镜对试样进行截面形貌、显微组织和成分的分析，运用EDS进行元素分析，放大20倍观察截面断口形貌，放大500、1000、2000倍来观察显微组织，利用XRD衍射仪对试样进行物相分析，分析试样相的组成。利用显微硬度计对试样进行硬度分析。主要研究了稀土La2O3粉末对激光增材制造多孔AZ61D合金的组织及性能影响。研究结果表明，（1）加入了稀土氧化镧后的AZ61D合金表面的球化现象稍有增多，表面有更多的气体缺陷。（2）多孔AZ61D合金中的α相为Mg，β相为Mg17Al12，加入了稀土氧化镧以后，在β相中，Al元素会和稀土元素La发生反应，生成稀土化合物Al11La3。（3）通过显微组织的观察，加入氧化镧后，晶粒明显获得细化。（4）硬度方面，加入氧化镧的AZ61D合金硬度提高了，力学性能更好了。关键词：选区激光熔化AZ61D镁合金稀土AbstractMgalloyisthelightestmetalstructuralmaterial,hashigherspecificstrengthandspecificrigidity,andhasstrongradiationresistance.Itcanbewidelyusedinaerospace,electronics,andmilitaryfields,andhasagoodspacefordevelopment.However,thelimitationsofitsprocessingandphysicochemicalpropertiesareactuallyverysmall,andthecastMgalloyhasmanyporedefectsandcoarsegrains.TheriseofselectivelasermeltingtechnologyisexpectedtopromotetheapplicationofMgalloys,andthepropertiesofalloysafteradditionofrareearthLa2O3powdershavealsoattractedatt...
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