镁合金倾斜薄壁电弧熔丝增材制造工艺与力学性能研究  

Deposition process and mechanical properties of magnesium alloy inclined thin-walls fabricated by wire-arc additive manufacturing

作　　者：郑元翾 韩启飞 陈斌凌 郭跃岭 谭醴 李星辰 彭司弋 刘长猛[1] ZHENG Yuanxuan;HAN Qifei;CHEN Binling;GUO Yueling;TAN Li;LI Xingchen;PENG Siyi;LIU Changmeng(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《材料工程》2024年第7期57-70,共14页Journal of Materials Engineering

摘　　要：电弧增材制造是一种以金属丝材为填充材料,以电弧作为热源的新型制造技术,易于制造大型复杂零件。通过往复单向路径实验,发现单向路径制造的斜壁有更好的形貌,飞溅少且表面光滑,并在有限元软件中建立了往复、单向制造路径仿真模型并求解,仿真得到单向路径沉积温度267.4℃,沉积热应力357.4 MPa,往复路径沉积温度307.0℃,沉积热应力420.4 MPa,发现单向路径的热积累和热应力更低;以单向制造路径,采用电弧增材制造技术制备AM11,AM12,AM21三种不同斜率的斜壁样件,研究其组织和力学性能。结果表明:AM11,AM12,AM21的晶粒尺寸分别为35,39,42μm;AM21薄壁晶粒中析出相β-Mg17Al12比另外两种样品多且分布均匀、拉伸断口的韧窝更大且更多;AM21与AM11显微硬度在81.5HV左右,均高于AM12的73.1HV;且AM21的斜壁样件的水平、竖直方向抗拉强度为255.7,224.4 MPa,屈服强度为103.8,96.0 MPa,伸长率达到13.1%,8.2%,抗拉强度与伸长率均大于AM11和AM12,但屈服强度接近。AM21斜率薄壁具有更好的强度和塑性,验证了镁合金电弧增材制造的斜壁越接近垂直,其强度、塑性等力学性能越好。Wire-arc additive manufacturing is a new type of manufacture using wire as filling material and arc as a heat source,making it easier to manufacture complex-shaped and big-sized parts.The reciprocating and unidirectional process path experiment was conducted.The inclined wall made by unidirectional path has better morphology,less splash,and a smoother surface.The simulation model of AM11 reciprocating and unidirectional manufacturing path was established in finite element software and solved.The simulation results show that the unidirectional path deposition temperature is 267.4℃,the deposition thermal stress is 357.4 MPa,the reciprocating path deposition temperature is 307.0℃,and the deposition thermal stress is 420.4 MPa,the heat accumulation and thermal stress of unidirectional path are lower than that of reciprocating path.AM11,AM12,and AM21 inclined wall samples with different slope factors by wirearc additive manufacturing in unidirectional path were prepared,and their microstructure and properties were analyzed.The results indicate that the grain size of AM11,AM12,and AM21 is 35,39μm,and 42μm,there is more precipitatedβ-Mg17Al12 in AM21 thin-walled grains,which has larger and more dimples than that of the other two samples.The micro-hardness values of AM21 and AM11 are both about 81.5HV,higher than 73.1HV of AM12.The horizontal and vertical tensile strengths of the AM21 inclined wall sample are 255.7,224.4MPa,the yield strengths are 103.8,96.0 MPa,and the elongations reach 13.1%and 8.2%.The tensile strengths and elongations are both greater than those of AM11 and AM12 samples,but the yield strengths are close.The AM21 inclined wall has much better strength and plasticity,and verify that the more perpendicular the inclined wall of magnesium alloy arc additive manufacturing is,the better the mechanical properties such as strength and plasticity.

关 键 词：电弧增材制造 AZ91D镁合金 薄壁件 微观组织 力学性能 断口组织 

分 类 号：TG44[金属学及工艺—焊接] TB31[一般工业技术—材料科学与工程]