Characterization of Mo–Si–B Nanocomposite Powders Produced Using Mechanical Alloying and Powder Heat Treatment
Characterization of Mo–Si–B Nanocomposite Powders Produced Using Mechanical Alloying and Powder Heat Treatment
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DOI：
10.1016/j.jmst.2015.07.007
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发表时间：
2015-10
影响因子：
10.9
通讯作者：
Bin Li;Guojun Zhang;F. Jiang;S. Ren;Gang Liu;Jun Sun
中科院分区：
文献类型：
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作者：
Bin Li;Guojun Zhang;F. Jiang;S. Ren;Gang Liu;Jun Sun
组成为Mo-12 Si-8.5 B（原子%）的Mo-Si-B纳米复合粉末在不同的研磨时间和粉球比的研磨条件下使用机械合金化处理。在1600 °C、50 MPa的压力下热压烧结得到了由α-Mo、Mo 3Si和T2相组成的Mo-12 Si-8. 5 B合金。结果表明，随着球磨时间的延长和粉球比的降低，粉末颗粒的尺寸和形貌逐渐细化和均匀。研磨15小时后，粉末在1：10和1：15的粉球重量比下完全均质化，并且由于其高研磨能量，加速均质化以快速稳定研磨过程。Mo-Si-B球磨粉末经900 °C低温退火后，可促进Mo 3Si和T2相的生长。提高退火温度只提高了各相的结晶度。经球磨和退火处理的粉末经热压烧结后，Mo-Si-B合金呈现出细晶组织，金属间化合物Mo 3Si和T2分布在连续的α-Mo基体中。
Mo–Si–B nanocomposite powders with a composition of Mo–12Si–8.5B (in at.%) were processed using mechanical alloying under milling conditions for different milling time and powder-to-ball ratios. The Mo–12Si–8.5B alloy, which consists of α-Mo and intermetallic Mo3Si and T2 phases, was also synthesized by hot-pressed sintering the mechanically alloyed powders under a pressure of 50 MPa at 1600 °C. The results demonstrated that the sizes and morphologies of the powder particles became gradually refined and uniform by both increasing the milling time and decreasing the powder-to-ball ratio. After 15 h of milling, the powders were completely homogenized at the 1:10 and the 1:15 powder-to-ball weight ratios, and the homogenization was accelerated to rapidly stabilize the milling process because of their high milling energy. Annealing the Mo–Si–B milled powders could promote the growth of the intermetallic Mo3Si and the T2 phases, which formed even after low-temperature annealing at 900 °C. Increasing the annealing temperature only improved the crystallinity of various phases. When the milled and annealed powders were hot-pressed sintered, the Mo–Si–B alloy exhibited a fine-grained microstructure, where the intermetallics Mo3Si and T2 were distributed in a continuous α-Mo matrix.