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以MoO3粉、Mo粉、Si粉及Al粉为原料,采用机械合金化法合成了纳米Mo5Si3-20%Al2O3(质量分数)复合粉体。采用XRD、SEM、TEM和DTA等对复合粉体在球磨过程中结构变化进行了研究。结果表明:球磨10h后合成的Mo5Si3-20%Al2O3复合粉体,反应以爆炸模式进行。球磨30h后,Mo5Si3和Al2O3的晶粒尺寸分别为36.3nm和21.9nm。随着球磨时间的延长,Mo5Si3和Al2O3的晶粒尺寸变小,衍射峰宽化程度降低。DTA和XRD分析结果表明,复合粉体具有好的热稳定性,球磨30h后再在1000℃退火1h后复合粉体没有发生物相转变。
Using MoO3 powder, Mo powder, Si powder and Al powder as raw materials, nano-Mo5Si3-20% Al2O3 (mass fraction) composite powders were synthesized by mechanical alloying. The structure changes of the composite powders during ball milling were studied by XRD, SEM, TEM and DTA. The results show that the reaction of Mo5Si3-20% Al2O3 synthesized by ball milling for 10h is carried out in an explosion mode. After milling for 30h, the grain sizes of Mo5Si3 and Al2O3 were 36.3nm and 21.9nm, respectively. With the increase of ball milling time, the grain size of Mo5Si3 and Al2O3 decreases, and the broadening of diffraction peak decreases. The results of DTA and XRD show that the composite powders have good thermal stability. No phase transformation occurs in the composite powders after being ball milled for 30h and then annealed at 1000 ℃ for 1h.