基于选区激光熔化成型生物医用Ti-6Al-4V合金的工艺与性能研究

发布时间：2018-01-23 22:46

  本文关键词： Ti-Al-V合金 选区激光熔化成型 显微组织 多孔网格结构　出处：《应用激光》2017年02期 　论文类型：期刊论文

【摘要】：Ti-6Al-4V合金具有强度高、抗蚀性优异、生物相容性好等优点,常用于制造医用多孔的植入体材料,但对多孔材料结构的成型工艺有一定的约束。基于选区激光熔化成型技术(Selective Laser Melting,SLM),结合自行设计的拓扑优化多孔网格结构,按照拓扑优化的结果重新建模成单元结构,进行了3组特殊结构(螺旋结构、拱形桥结构、薄壁件与小孔)的制造实验,并且分析对比了热处理前后SLM制造的Ti-6Al-4V合金的显微组织和拉伸性能。研究结果表明,SLM成型的三种螺旋结构中,除30°螺旋结构以外,其他两种都能够完整成形,满足拓扑单元结构成形角度(≥45°)的制造,30°螺旋结构通过在迎向刮刀锐角面下加少量支撑也能成形;拱形桥实验中,能够完整成型不发生塌陷的最大拱桥尺寸为φ=8mm,推导出最大的可悬垂长度为0.70mm,满足拓扑单元结构最大拱桥尺寸(8mm)要求;壁厚为0.10mm的薄壁结构由于激光光斑尺寸的约束,成形尺寸增大了0.05mm,可能会造成1mm边长尺寸成单元拓扑结构孔隙率的减小;小孔实验成形最小孔径为0.10mm,满足多孔拓扑优化结构最小孔制作要求;SLM制造直接态和热处理态Ti-6Al-4V合金试样基本的力学性能均能达到ISO制定力学性能标准,且超过铸造态的水平,但延展性能仍不及锻件。热处理态比直接态的延展性好,直接态组织为针状的α′相马氏体组织;当热处理温度达到750℃时,α′相会开始发生扩散分解,从而在相界面析出白色的β相小颗粒。
[Abstract]:Ti-6Al-4V alloys have many advantages such as high strength, excellent corrosion resistance and good biocompatibility. However, there are some constraints on the forming process of porous material structure. Based on selective laser melting technology, selective Laser melting process (SLM). Combined with the self-designed topology optimization porous mesh structure, according to the result of topology optimization, the unit structure is remodeled, and three groups of special structures (spiral structure, arch bridge structure) are carried out. The microstructure and tensile properties of Ti-6Al-4V alloy made by SLM before and after heat treatment were analyzed and compared. Among the three kinds of helical structures formed by SLM, except 30 掳helical structure, the other two kinds of helical structures can be formed completely, which can satisfy the manufacturing of the forming angle (鈮，

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