Laser-beam powder bed fusion of cost-effective non-spherical hydride-dehydride Ti-6Al-4V alloy
Laser-beam powder bed fusion of cost-effective non-spherical hydride-dehydride Ti-6Al-4V alloy
复制标题
DOI：
10.1016/j.addma.2022.102875
复制
发表时间：
2022-05
影响因子：
11
通讯作者：
Mohammadreza Asherloo;Ziheng Wu;Melody H. Delpazir;Eyob Ghebreiesus;S. Fryzlewicz;R. Jiang;B. Gould;M. Heim;Dave Nelson;M. Marucci;M. Paliwal;A. Rollett;A. Mostafaei
中科院分区：
文献类型：
--
作者：
Mohammadreza Asherloo;Ziheng Wu;Melody H. Delpazir;Eyob Ghebreiesus;S. Fryzlewicz;R. Jiang;B. Gould;M. Heim;Dave Nelson;M. Marucci;M. Paliwal;A. Rollett;A. Mostafaei
具有非球形颗粒形态的氢化-脱氢（HDH）Ti-6Al-4V粉末通常不用于激光束粉末床熔合（LB-PBF）。在此，比较了具有50-120 µm（细）和75-175 µm（粗）两种粒度分布的HDH粉末的流动性、堆积密度和LB-PBF制造部件的所得密度。结果表明，在HDH Ti-6Al-4V粉末的LB PBF中，采用合适的激光功率-速度-开口间距组合，可获得致密度> 99.5%的零件。在2D中分析孔的尺寸、形态和空间分布。对未熔合和小孔孔隙形成区域的边界进行了评估，结果表明，相对密度> 99.5%的零件可以在LPBF机器中以标称生产率的1.5-2倍的构建率进行LPBF处理。同步辐射X射线高速成像揭示了激光-粉末相互作用和与HDH粉末相关的潜在孔隙形成机制。结果表明，在LB-PBF过程中，粗粉的堆积密度较低，小孔波动较大，导致造坯中孔隙率较高。
Hydride-dehydride (HDH) Ti-6Al-4V powders with non-spherical particle morphology are typically not used in laser-beam powder bed fusion (LB-PBF). Here, HDH powders with two size distributions of 50–120 µm (fine) and 75–175 µm (coarse) are compared for flowability, packing density, and resultant density of the LB-PBF manufactured parts. It is shown that a suitable laser power-velocity-hatch spacing combination can result in part production with a relative density of > 99.5% in LB-PBF of HDH Ti-6Al-4V powder. Size, morphology, and spatial distribution of pores are analyzed in 2D. The boundaries of the lack-of-fusion and keyhole porosity formation regimes are assessed and results showed parts with a relative density of > 99.5% could be LPBF processed at a build rate of 1.5–2 times of the nominal production rates in LPBF machines. The synchrotron x-ray high-speed imaging reveals the laser-powder interaction and potential porosity formation mechanism associated with HDH powder. It is found that lower powder packing density of coarse powder and high keyhole fluctuation result in higher fractions of porosity within builds during the LB-PBF process.