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目的 改善Ti-6 Al-4 V钛合金的组织性能. 方法 使用离心研磨工艺对Ti-6 Al-4 V钛合金进行表面处理,通过显微硬度计、X射线应力分析仪、金相显微镜,对不同加工时间下试样表层的显微硬度、残余应力、金相组织进行测试. 结果 离心研磨加工后,Ti-6Al-4V钛合金表面的显微硬度得到提高,试样最表面的显微硬度随加工时间的延长呈现逐渐增大的趋势,加工时间为40 min时,显微硬度达到最大值385HV,比试样基体硬度值提高了55HV;在加工深度方向上,随着深度的增加,显微硬度值逐渐降低,在深度为400 μm附近,显微硬度值已与基体硬度值相差不大,并且基本不再下降. 加工完成后,试样表面产生了有益的残余压应力,最大残余压应力值为436 MPa. 金相组织分析结果表明,试样表层组织形成了剧烈塑性变形层,其深度约40 μm,在变形层内,组织的晶粒得到明显细化. 结论 离心研磨抛光工艺对Ti-6Al-4V钛合金表面组织性能改善效果明显,验证了使用该工艺对Ti-6Al-4V钛合金进行表面强化的可行性.

Objective To improve the microstructure properties of Ti-6Al-4V titanium alloys. Methods In this paper, the sur-face of Ti-6Al-4V titanium alloy was treated by centrifugal grinding process. The microhardness, residual stress and microstructure of specimen surface were analyzed by using microhardness tester, X-ray stress analyzer and metallographic microscope. Results The test results showed that when the processing was completed, the microhardness got increased, the microhardness on the sample presented a gradually increasing trend with the extension of processing time, when the processing time reached 40 min, the micro-hardness reached a maximum of 385 HV, improved by 55 HV than the sample matrix's microhardness. In the direction of process-ing depth, the microhardness value gradually reduced with the increase of depth. At the depth of 400μm, the microhardness value no longer decreased, and was close to the matrix microhardness. The residual stress was generated on the surface of workpiece after processing and the maximum residual stress was 436 MPa. The microstructure analysis results showed that the workpiece surface tissue produced severe plastic deformation layers, the depth of which was about 40μm, the grain was fined obviously within the de-formation layer. Conclusion The centrifugal grinding process significantly improved the microstructure properties of Ti-6Al-4V tita-nium alloy and validated the feasibility of this processing for strengthening the surface of Ti-6Al-4V titanium alloy.