摘要
FeAl金属间化合物具有优良的物理性能和力学性能,但其室温塑性和断裂韧性低,限制了其工程应用。利用机械合金化制备了Fe(Al)固溶体合金粉末及Al2O3,WC硬质相增强的复合合金粉末,通过冷喷涂沉积涂层并结合后热处理原位反应制备了FeAl金属间化合物涂层及其复合涂层。利用扫描电镜(SEM)、X射线衍射仪(XRD)及显微硬度仪等研究了硬质相对球磨粉末组织结构、冷喷涂FeAl金属间化合物涂层组织结构及性能的影响。结果表明,硬质相可显著加速球磨粉末内部层状结构的细化程度,喷涂态涂层具有不同于传统热喷涂涂层的层状组织结构,热处理可实现喷涂态涂层中Fe(Al)固溶体向FeAl金属间化合物的原位转变,致使层状结构消失,获得无粒子界面的FeAl金属间化合物涂层,弥散分布的硬质相可显著提高冷喷涂FeAl金属间化合物涂层的强化稳定性。
FeAl intermetallic compounds had excellent physical and mechan-ical properties. However,their industrial applications were limit-ed by low room temperature ductility and fracture toughness. Thus FeAl intermetallic compound coating and the same coatings rein-forced with hard phases Al2O3 and WC were in-situ prepared by cold spraying of mechanically alloyed Fe( Al) solid solution alloy powder,Fe(Al)/Al2O3 and Fe( A1)/WC composite powder and follow-up post-spraying heat treatment. The influence of hard phases Al2O3 and WC on the microstructure,phase composition and microhardness of cold-sprayed FeAl-based composite coatings was investigated by means of scanning electron microsco-py,X-ray diffraction and microhardness testing. Results show that the hard phases can accelerate the microstructure refinement of ball-milled powder. The as-sprayed coatings exhibited the same composition and structure as those of ball-milled materialsfor spraying. Moreover,heat treatment resulted in the complete transformation from Fe( Al) solid solution to FeAl intermetallic compound and enhanced interfacial bonding of deposited parti-cles. The dispersed hard phases could significantly increase the microhardness of the cold-sprayed FeAl intermetallic compound coatings.
出处
《材料保护》
CAS
CSCD
北大核心
2010年第4期90-94,共5页
Materials Protection
