CoCrMoW合金的粉末特性及其激光选区熔化成形性能研究

Research on the Powder Characteristics and Selective Laser Melting Forming Properties of CoCrMoW Alloy

摘要:

利用真空气雾化技术制备激光选区熔化成形用CoCrMoW合金粉末，检测分析了粉末的特性，引入椭圆延伸度、ISO圆度、赘生物指数来定量表征粉末的粒形和卫星粉，并研究了该粉末的SLM成形性能和电化学性能。结果表明：粉末的D10、D50、D90分别为：12.50μm、28.71μm、58.05μm；大部分粉末在形状上为球形和近球形，粉末平均椭圆延伸度为0.212，平均ISO圆度为0.607，表面没有粘连微粒的粉末占总体积的74.89%；粉末的松装密度为4.82g/cm3，振实密度为5.71g/cm3，压缩度为15.6%。粉末适用于激光选区熔化成形，成形试样致密度达到98.7%，表面粗糙度为8.3μm；显微硬度为396HV，抗拉强度为1154MPa，屈服强度为852 MPa，延伸率为8.5%，且耐腐蚀性能优于铸造CoCr合金。

Abstract:

CoCrMoW alloy powder for 3D printing was prepared by vacuum gas atomization. Particle characteristics was studied and the Ell.Elongation, ISO Circularity, Outgrowth were introduced to characterize the particle shape. And the Selective Laser Melting forming properties of the powders and electrochemical properties of the formed parts were studied. Results indicate that the measured D10, D50 and D90 are 12.50 μm, 28.71 μm and 58.05 μm, respectively. Majority powder particles are spherical or near spherical in shape and the mean Ell.Elongation and ISO Circularity are 0.212 and 0.607, respectively. About 74.89% of the powder particles have no adhesion on the surface. The apparent density and tap density are 4.82 g/cm3 and 5.71 g/cm3, the compressibility is 15.6 %. The CoCrMoW powder was used for Selective Laser Melting and the relative density and surface roughness are 98.7% and 8.3 μm, respectively. The microhardness, tensile strength, yield strength and elongation are 396.4 HV, 1154 MPa, 852 MPa and 8.5%, respectively. And the corrosion resistance of CoCrMoW alloy prepared by Selective Laser Melting is better than that of the cast alloy.