超重力场辅助燃烧合成Mo合金

Fabrication of Mo alloy by Combustion Synthesis under High Gravity

摘要:

以Al、MoO₃、SiO₂和B₂O₃为原料,采用超重力场辅助燃烧合成的方法制备了Mo合金,并研究了B₂O₃组分含量对Mo合金的物相组成、微观结构和力学性能的影响。在1000g超重力场作用下,燃烧合成生产的金属与陶瓷熔体快速分离和凝固,获得致密度高的Mo合金样品。采用X射线衍射(XRD)、扫描电子显微镜(SEM)对Mo合金的物相组成和微观形貌进行了研究。对反应合成产物的X射线衍射分析表明,随着B₂O₃组分含量的增加,产物中有新相生成,新相的主要成分为Mo₃Si和Mo₅SiB₂。结果表明：当反应物B₂O₃组分的质量分数由0增加至12%,产物Mo合金的密度由9.76g/cm₃下降至9.35g/cm₃,硬度由300MPa增加至1035MPa,抗弯强度由711MPa下降至460MPa。在超重力场的作用下,B₂O₃含量的增加促进了新相的产生,新相Mo₃Si和Mo₅SiB₂的产生对Mo合金起到了增强的作用。

Abstract:

Mo alloy was prepared with Al, MoO₃, SiO₂ and B₂O₃ as raw materials by combustion synthesis under high gravity, and the effects of B₂O₃ contents on the phase composition, microstructure and mechanical properties of the prepared Mo alloy were discussed. In a high gravity field with an acceleration of 1000g, the metal melt and ceramic melt obtained by combustion synthesis were rapidly separated. After cooling and solidification, the dense Mo alloy was obtained. The phase composition and microstructure of the Mo alloy were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM). The XRD results show that with the increasing of the B₂O₃ contents, there was a new phase in the product. And the new phase was composed of Mo₃Si and Mo₅SiB₂. It is found that when the contents of B₂O₃ increased from 0 to 12wt%, the density of the prepared Mo alloy was dropped from 9.76g/cm₃ to 9.35g/cm₃; hardness was increased from 300MPa to 1035MPa and flexural strength was dropped from 711MPa to 460MPa. In a high gravity field, the increasing of the B₂O₃ contents promoted the formation of the new phase which was composed of Mo₃Si and Mo₅SiB₂, and the new phase played an important role in enhancing the Mo alloy.