摘要
目的利用激光渗碳磨技术,研究Ti6Al4V表面性-形协同控制机理。方法以Ti6Al4V为研究对象,提出了一种高效的加工强化一体化技术——激光渗碳磨削。即对工件表面预涂覆渗碳膏,并置于马弗炉中干燥,形成稳定的固态碳源。采用激光辅热的方式对磨削加工过程进行表面性形协同抗疲劳制造。通过对比实验研究了激光渗碳磨削和传统磨削对Ti6Al4V表面力学性能和加工表面质量的影响。对Ti6Al4V表面微相组成、硬度、耐磨性和表面粗糙度进行表征。探究了激光渗碳合金化对材料磨削去除的正向作用以及磨削热回火对重熔层性能的调节作用。结果激光辅热足以使磨削表面温度高达1700℃,实现表面主动渗碳,且激光渗碳磨削后,Ti6Al4V表面形成具有均匀树枝状晶和颗粒状碳化物的重熔层,加工表面硬度达到850HV,磨损损失仅为常规磨削的6.7%,表面粗糙度Ra降低22%。结论激光渗碳磨是一种高效的Ti6Al4V表面性-形协同制造新技术。渗碳重熔层不仅提高了加工表面力学性能,还会影响表层材料的磨削特性,使加工表面更加光整。该技术实现了磨削加工-强化一体化制造,对指导工业生产具有重要的实际意义。
Titanium alloy is considered as the superalloy and widely utilized in military,aerospace,biomedicine,and marine engineering for its special strength and property.Moreover,high-performance Ti6Al4V surfaces are in great demand in aerospace,military,automotive manufacturing and marine engineering.Many surface strengthening methods are applied in Ti6Al4V,such as electrochemical anodic oxidation,chemical vapor deposition,and plasma spraying technology.However,Ti6Al4V surface machining and strengthening technologies face challenges in balancing productivity,energy consumption and equipment cost.Nowadays,the laser technology has become a hot topic in the key part manufacture.The high precision surface removal is required to improve the surface quality.It can be found that these two procedures seem complicated and time-consuming.Immortally,the productivity rate decreases as well.To fill these gaps,an efficient integrated Ti6Al4V machining and strengthening technology,laser carburizing grinding,is proposed to study the control mechanism of property-shape synergistic manufacturing technology.With the help of the property-shape synergistic manufacturing method,the Ti6Al4V surface with higher strength can be obtained efficiently.The workpiece was coated by the carbon carburization paste,which was mixed by the carbon powder,the starch and the PVA-1799.Afterwards,the coated workpiece was set in the muffle furnace and was heated for 15 min at the temperature of 150℃.Therefore,the workpiece with the ready-made solid carbon source could be obtained.After the experiment item was confirmed,the grinding was conducted on the carbon coated workpiece assisted by the laser heating.The macroscopic characterization of the ground surface was testified by the force measurement,the temperature paperless recorder,the metallographic microscope,the microhardness tester,and the friction wear tester.The effects of laser carburizing grinding and conventional grinding on the mechanical properties and machining accuracy of Ti6Al4V surfaces were investigated by the designed comparative experiments.The microphase composition,microhardness,wear resistance and surface roughness of Ti6Al4V surfaces were characterized.Moreover,the positive effect of laser carburizing alloying on material removal by grinding and the modulating effect of grinding heat tempering on remelted layer properties were revealed.During the whole material removal process,the workpiece surface experienced two temperature rising process,which was on account of the grinding tempering process and the laser heating process respectively.The grinding tempering process could arise the surface temperature at 300℃.The assisted laser heating could arise the surface temperature at 1700℃,and the higher temperature could cause the surface active carburization and the microstructure transformation.After laser carburizing grinding,the dendritic shape and granular shape microstructure could be observed at the laser grinding carburization surface.The surface microhardness of Ti6Al4V can reached 850HV,the wear loss was only 6.7%of that by conventional grinding,and the surface roughness Ra was reduced by 22%.To sum up,the proposed composite processing technology is beneficial for higher strength surface with higher precision compatibly.This study proposes a new technology of Ti6Al4V surface property-shape synergistic manufacturing,which fills the grinding processing-strengthening integration theory gap and has important practical significance in guiding industrial production.
作者
邓延生
曹长虹
陶彦辉
孙聪
DENG Yansheng;CAO Changhong;TAO Yanhui;SUN Cong(Jihua Laboratory,Guangdong Foshan 528000,China;Xinjiang Institute of Engineering,Urumchi 830023,China;Northeastern University,Shenyang 110819,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2024年第18期167-174,共8页
Surface Technology
基金
广东省实验室重点项目(X190301TH190)
晶圆减薄金刚石砂轮磨块材料溶胶凝胶法制备技术开发(S230551VB230)
国家自然科学基金资助项目(52105433)。
关键词
TI6AL4V
激光渗碳磨削
性-形协同控制
加工强化一体化
Ti6Al4V
laser carburizing grinding
property-shape synergistic manufacturing
processing-strengthening integration
作者简介
通信作者:邓延生;通信作者:曹长虹。
