Effect of Powder Particle Shape on the Properties of In Situ Ti-TiB Composite Materials Produced by Selective Laser Melting
Effect of Powder Particle Shape on the Properties of In Situ Ti-TiB Composite Materials Produced by Selective Laser Melting
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DOI：
10.1016/j.jmst.2015.08.007
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发表时间：
2015-10-01
影响因子：
10.9
通讯作者：
Eckert, Juergen
中科院分区：
文献类型：
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作者：
Attar, Hooyar;Prashanth, Konda G.;Eckert, Juergen
研究了球磨时间对初始粉末制备的影响，以及球磨时间对选择性激光熔化（SLM）原位合成Ti-TiB复合材料的颗粒形貌（尤其是形状）、致密度和压缩性能的影响。通过混合95wt%商业纯钛（CP-Ti）和5wt%二硼化钛（TiB 2）粉末并随后研磨两个不同的时间（即2小时和4小时）来制备起始粉末复合物体系。研磨的粉末混合物在2小时和4小时后分别显示出接近球形和不规则形状。随后，将所得Ti-5重量% TiB 2粉末混合物用于SLM加工。扫描电子显微镜图像的SLM处理的Ti-TiB复合材料样品显示针状TiB相分布在整个Ti基体，这是在SLM过程中的Ti和TiB 2之间的原位化学反应的产物。球磨2 h和4 h的Ti-TiB_2粉末制备的Ti-TiB复合材料样品的相对密度分别为99.5%和95.1%。此外，99.5%致密的复合材料样品的压缩性能，如极限强度和压缩应变分别为1421 MPa和17.8%，这是上级优于那些（883 MPa和5.5%，分别为95.1%致密的样品）。结果表明，一旦Ti和TiB 2粉末彼此牢固连接并且获得接近球形的粉末混合物，则增加研磨时间没有额外的益处，相反，它对Ti-TiB复合材料的密度（即增加孔隙率水平）及其机械性能具有负面影响。材料科学与技术学报编辑部版权所有（C）2015出版社：Elsevier Limited All rights reserved.
This work studied the preparation of starting powder mixture influenced by milling time and its effect on the particle morphology (especially the shape) and, consequently, density and compression properties of in situ Ti-TiB composite materials produced by selective laser melting (SLM) technology. Starting powder composite system was prepared by mixing 95 wt% commercially pure titanium (CP-Ti) and 5 wt% titanium diboride (TiB2) powders and subsequently milled for two different times (i.e. 2 h and 4 h). The milled powder mixtures after 2 h and 4 h show nearly spherical and irregular shape, respectively. Subsequently, the resultant Ti-5 wt% TiB2 powder mixtures were used for SLM processing. Scanning electron microscopy image of the SLM-processed Ti-TiB composite samples show needle-shape TiB phase distributed across the Ti matrix, which is the product of an in-situ chemical reaction between Ti and TiB2 during SLM. The Ti-TiB composite samples prepared from 2 h and 4 h milled Ti-TiB2 powders show different relative densities of 99.5% and 95.1%, respectively. Also, the compression properties such as ultimate strength and compression strain for the 99.5% dense composite samples is 1421 MPa and 17.8%, respectively, which are superior to those (883 MPa and 5.5%, respectively) for the 95.1% dense sample. The results indicate that once Ti and TiB2 powders are connected firmly to each other and powder mixture of nearly spherical shape is obtained, there is no additional benefit in increasing the milling time and, instead, it has a negative effect on the density (i.e. increasing porosity level) of the Ti-TiB composite materials and their mechanical properties. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.