超声微锻Ti_(3)Al熔覆层组织与性能的实验研究  

Experimental Study on Organization and Properties of Ultrasonic Micro-forging Ti_(3)Al Cladding Layers

作　　者：高国富[1] 潘贤荣 常黎明[1] 王得宇 赵波[1] GAO Guo-fu;PAN Xian-rong;CHANG Li-ming;WANG De-yu;ZHAO-Bo(Henan Polytechnic University,Henan Jiaozuo 454003,China)

机构地区：[1]河南理工大学,河南焦作454003

出　　处：《表面技术》2023年第8期433-443,共11页Surface Technology

基　　金：国家自然科学基金(51875179)。

摘　　要：目的采用超声振动与微锻技术相结合的表面改性技术,在Ti-6Al-4V基体上获得组织优良、物理性能好的Ti_(3)Al熔覆层。方法搭建超声微锻装置,采用单因素实验研究超声振幅、加工温度、锻打力、锻打时间对熔覆层金相组织、晶粒以及显微硬度的影响规律。借助金相显微镜(OM)、扫描电子显微镜(SEM)、显微硬度计对熔覆层的宏观形貌、微观组织及显微硬度进行分析和测试。结果在超声微锻处理下,熔覆层组织与性能得到显著改善。熔覆层表面平整度与超声振幅呈正相关,随着超声振幅、锻打力的增大,粗大的树枝状α_(2)相逐渐锻碎细化为大量的短棒状α_(2)相和针状α_(2)相以及少量的片层状α_(2)相和等轴α_(2)相,等轴晶的含量与分布范围增大,晶粒细化效果越来越明显。熔覆层各区域的显微硬度值均随着超声振幅、锻打时间的增加而有不同程度的提高。当超声振幅为7μm时,熔覆层顶部、中部、底部的显微硬度分别提高了18.4%、22.8%、51.5%。当锻打时间为5 s时,熔覆层顶部、中部、底部的显微硬度分别提高了15.5%、15.8%、37.8%。熔覆层顶部显微硬度值随着锻打力的增大呈现出逐渐升高的趋势,显微硬度最高可达55.1HRC,其他区域的硬度呈现逐渐降低的趋势。结论超声微锻能够有效改善熔覆层的宏观形貌以及内部组织,细化晶粒,选择合适的工艺参数可进一步提高其显微硬度值。因此,超声微锻可作为一种有效的熔覆层改性技术。The work aims to achieve Ti_(3)Al cladding layers with superior structure and good physical properties on Ti-6Al-4V substrate,by applying the surface modification technology combining ultrasonic vibration and micro-forging.In this work,a ultrasonic micro-forging device was built and the effect of ultrasonic amplitude,processing temperature,forging force and forging time on the metallographic organization,grain size and microhardness of the cladding layer was investigated by single-factor test.The macroscopic morphology and microstructure of the forged cladding layer were observed by a metallographic microscope(OM)and a scanning electron microscope(SEM).The microhardness of the forged cladding layer was studied through a microhardness tester.The structure and properties of the forged cladding layer were significantly improved by ultrasonic micro-forging treatment.The surface flatness of the forged cladding layer was positively correlated with the ultrasonic amplitude.With the increase of ultrasonic amplitude and forging force,the refinement degree of the coarse dendriticα_(2)phase breaking down into a large number of short rod-shapedα_(2)phases and needle-shapedα_(2)phases,along with a small amount of lamellarα_(2)phases and equiaxedα_(2)phases became more comprehensive.The content and distribution range of equiaxed crystals increased,and the grain refinement effect became more evident.The microhardness of each region of the forged cladding layer increased to some extent with the increase of ultrasonic amplitude and forging time.When the ultrasonic amplitude was 7μm,the microhardness of the top,the middle and the bottom of the forged cladding layer increased by 18.4%,22.8%,and 51.5%respectively.When the forging time was 5 s,the microhardness of the top,the middle and the bottom of the forged cladding layer increased by 15.5%,15.8%,and 37.8%respectively.The microhardness of the top of the forged cladding layer appeared an increasing trend with the increase of forging force,and the microhardness was up to 55.1

关 键 词：超声微锻 Ti_(3)Al 熔覆层 微观组织 显微硬度 工艺参数 

分 类 号：TG174[金属学及工艺—金属表面处理]