摘要
利用等离子喷涂和重熔技术制备多孔型镍基自熔性合金涂层,采用扫描电镜、显微硬度计、材料试验机、热膨胀仪等设备对涂层的微观组织、热膨胀系数和压缩过程中的力学性能进行分析。结果表明,涂层中存在封闭孔洞,大部分呈近似球形,直径在30~100μm;孔隙率由0.53%上升至30.6%时,涂层材料的弹性模量下降69.5%,弹性变形范围上升68.7%;在40~220℃的范围内,多孔涂层的平均线膨胀系数随着孔隙率的增加而下降。近球形闭孔的存在提升了原有材料的弹性变形范围,降低了热膨胀系数,使其可以实现低膨胀、高回弹的功能。
A porous Ni-based coating was fabricated by plasma spraying and subsequent remelting. The microstructure, thermal expansion coefficient and mechanical properties during compression process were analyzed by scanning electron microscope （SEM）, micro-hardness tester, thermophysical properties instruments and so on. The results show that the closed and spherical pores with 30-100 p,m in diameter are formed in the remelted coating. The elastic modulus of the porous coating descends by 69.5% and elastic deforming scope ascends by 68.7% with the porosity increasing to 30.6% from 0.53%. The average linear thermal expansion coefficient decreases with the increasing of porosity in the temperature scope between 40 and 220 ℃. The improvement of elastic deforming scope of Ni-based alloy due to the formation of closed pore results in the decline of thermal expansion coefficient, to achieve the purpose of low thermal expansion and high recoverability.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2018年第1期219-222,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51501222)
天津市应用基础与前沿技术研究计划项目(14JCQNJC06800)
中央高校基本科研业务费中国民航大学专项资助项目(3122015L001)
关键词
镍基合金
封闭孔洞
弹性模量
弹性变形范围
热膨胀系数
Ni-based alloy
closed pore
elastic modulus
elastic deforming scope
thermal expansion coefficient
