医用锻造CoCrMo合金等离子氮化微观结构及摩擦性能（英文）  

Microstructure and Tribological Properties of Plasma Nitrided Biomedical CoCrMo Alloys

作　　者：徐林[1] 巴德纯[1] 王庆[1] 蔺增[1] 

机构地区：[1]东北大学,辽宁沈阳110819

出　　处：《稀有金属材料与工程》2017年第1期51-56,共6页Rare Metal Materials and Engineering

基　　金：Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(2014475)

摘　　要：采用高压直流等离子体氮化技术,对医用锻造钴铬钼合金进行表面氮化处理,考察了氮化温度及时间对钴铬钼合金摩擦性能及润湿性能的影响。运用X射线衍射仪及场发射扫描电镜分析氮化层物相组成及表面微观结构;用显微硬度计和光学动/静态接触角仪测试合金表面显微硬度及接触角数值;利用球-盘摩擦试验机在干摩擦条件下对氮化层的摩擦磨损性能进行测试。结果表明:钴铬钼合金试样经直流等离子体氮化处理后,氮化层厚度、表面粗糙度及显微硬度值显著增加,亲水性能及耐磨损性能得到明显改善。在较低的氮化温度及较短的氮化时间内,氮化试样物相主要由σ-CoCr相及CrN相组成;随着氮化温度及时间的增加,氮化试样物相中还检测到硬质化合物相Cr_2N。与未处理试样相比,氮化试样的磨损率及磨痕宽度减小,氮化参数为800°C/8 h时磨损率最低,磨痕宽度最窄,耐磨损性能最佳。Medical forged Co Cr Mo alloy was treated by DC plasma nitriding process to alter its surface characteristics and to improve mechanical and tribological properties. The phase composition, microstructures, surface microhardness, and wettability were characterized by X-ray diffraction, scanning electron microscope, micro-hardness tester, and optical dynamic/static contact angle meter. Friction and wear characteristics were investigated on ball-on-disc tribotester under dry sliding conditions. The experimental analysis confirms that the plasma nitriding process is promising in producing thicker, harder, highly hydrophilic and more wear resistance layers on Co Cr Mo alloy for biomedical applications. At lower nitriding temperatures and for shorter time, the nitrided layer structure is composed of σ-Co Cr and Cr N phases. At higher nitriding temperatures and for longer time, σ-Co Cr and Cr N as well as Cr_2 N phases appear in nitrided specimens. With the increasing of nitriding temperatures and time, case depth thickness, surface roughness, microhardness and wear resistance increase while water contact angle decreases and becomes highly hydrophilic. Compared with untreated Co Cr Mo alloy, all nitrided specimens show an important reduction in wear rate and wear scar width, and the nitrided specimen at 800 °C/8 h exhibits the lowest wear rate and the best dry-sliding wear resistance.

关 键 词：医用锻造钴铬钼合金 高压直流等离子体氮化 显微硬度 润湿性 摩擦性能 

分 类 号：TG156.82[金属学及工艺—热处理]