摘要
目的针对激光熔覆制备IN 625高温合金涂层时易产生缺陷和元素偏析进而导致合金性能下降的问题,提高增材制造IN 625高温合金的力学性能。方法在激光熔覆IN 625涂层的过程中施加超声振动辅助,通过物相检测和微观组织观测研究超声功率对涂层物相种类和晶体尺寸的影响;通过分析析出相含量、分布方式及析出形态,研究超声功率对元素偏析的影响;通过对显微硬度、高温耐磨性进行测试,研究超声功率对涂层力学性能的影响。结果施加超声前的涂层组织主要为方向杂乱的粗大枝晶,施加超声后的涂层物相组成未发生明显变化,但枝晶内亚晶排列紧密且尺寸明显减小;施加超声振动后的涂层析出相尺寸减小、含量下降,其中Laves相含量在施加超声后降幅较大,表明超声振动可以抑制Nb、Mo等元素的偏析;施加超声振动后涂层的显微硬度提高,磨损率明显下降,磨损机制由原来的表面疲劳磨损、黏着磨损和磨粒磨损的复杂磨损转变为磨粒磨损、黏着磨损的简单磨损。结论施加超声辅助可以有效细化IN 625涂层组织,并抑制Laves相的析出,提高涂层的硬度和耐磨性。
The work aims to improve the mechanical properties of additive manufactured IN 625 high-temperature alloy,so as to solve the problem of property decline caused by the defects and element segregation during laser cladding.The ultrasonic vibration assistance was applied in the process of laser cladding of IN 625 coating.The effect of ultrasonic power on phase type and crystal size of IN 625 coating was studied by phase detection and microstructure observation.The effect of ultrasonic power on element segregation was studied by analyzing the content,distribution and form of precipitated phase.The effect of ultrasonic power on the mechanical properties of the coating was studied by testing the microhardness and high temperature wear resistance.The microstructure of the coating was mainly coarse dendrites with disordered direction before the application of ultrasonic vibration.The phase composition of the coating did not change significantly after the application of ultrasonic vibration,but the subcrystals were closely arranged and the size decreased obviously.After the application of ultrasonic vibration(UV),the size and content of precipitated phase of the coating decreased,and the content of Laves phase decreased greatly after the application of ultrasonic vibration,indicating that ultrasonic vibration could inhibit the segregation of Nb,Mo and other elements.After ultrasonic vibration was applied,the microhardness of the coating increased and the wear rate decreased obviously.The wear mechanism changed from the original complex wear of surface fatigue wear,adhesive wear and abrasive wear to the simple wear of abrasive wear and adhesive wear.The ultrasonic vibration can effectively refine the microstructure of the IN 625 coating,inhibit the precipitation of Laves phase,and improve the microhardness and wear resistance of the coating.
作者
牛庆伟
郝敬宾
纪皓文
付天池
杨海峰
刘昊
NIU Qingwei;HAO Jingbin;JI Haowen;FU Tianchi;YANG Haifeng;LIU Hao(School of Mechanical and Electrical Engineering,China University of Mining and Technology,Jiangsu Xuzhou 221116,China;Yunlong Lake Laboratory of Deep Underground Science and Engineering,Jiangsu Xuzhou 221116,China)
出处
《精密成形工程》
北大核心
2024年第2期137-148,共12页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52275224,52375223)
徐州市基础研究计划面上项目(KC23075)。
关键词
激光熔覆
超声振动
高温合金涂层
摩擦磨损
元素偏析
laser cladding
ultrasonic vibration
high-temperature alloy coating
friction and wear
element segregation
