Investigation on surface integrity of electron beam melted Ti-6Al-4 V by precision grinding and electropolishing  

作　　者：Jiang GUO Min Hao GOH Pan WANG Rui HUANG Xiaohua LEE Bin WANG Sharon Mui Ling NAI Jun WEI 

机构地区：[1]Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education,Dalian University of Technology,Dalian 116024,China [2]Ningbo Institute of Dalian University of Technology,Ningbo 315016,China [3]Singapore Institute of Manufacturing Technology,Singapore 637662,Singapore [4]Harbin Institute of Technology,Shenzhen 518055,China

出　　处：《Chinese Journal of Aeronautics》2021年第12期28-38,共11页中国航空学报（英文版）

基　　金：financial support from LiaoNing Revitalization Talents Program(No.XLYC1807230);A*STAR Industrial Additive Manufacturing Program:Work Package 3(Electron Beam Melting,No.1325504103);Liaoning Natural Science Foundation Guidance Plan(No.20180550171)。

摘　　要：Electron beam melting(EBM),as an excellent Additive Manufacturing(AM)technology,enables the printing of Ti-6Al-4V alloy for a wide range of applications such as aerospace and biomechanical industries.It improves functionality and integrity of components and negates complexities in assembly processes.However,due to the poor surface and sub-surface integrity represented by the rough surface finish and low dimensional accuracy,achieving a favorable surface condition is quite challenging.Therefore,post processing becomes essential for these electron beam melted(EBM-ed)Ti-6Al-4V alloys.Being the most common technique to improve such parts,milling of Ti-6Al-4V alloy is very challenging and resulting tool wear issues,due to its unique material properties.Thus,this paper presents a comprehensive study on the surface integrity of EBM-ed Ti-6Al-4V parts processed by precision grinding and electropolishing,aiming to qualitatively and quantitatively clarify the interrelation between process parameters and processed surface quality.The surface and subsurface characteristics such as profile accuracy,surface roughness,microstructure,defective layer and residual stress before and after post processing were compared and evaluated.The results show that by precision grinding,the profile accuracy was improved from over 300μm PV to 7μm PV,while surface roughness(R_(a))was reduced from 30μm to about 2μm.The layer with partially melt particles was removed,but introduced a deformed subsurface layer with more residual stress.Then by applying electropolishing,the residual stress was released and the deformed layer was removed.In addition,Ra was further reduced to 0.65μm.The research can serve as a reference for the integration of post machining processes with AM.

关 键 词：Additive Manufacturing(AM) Electron Beam Melting(EBM) ELECTROPOLISHING GRINDING Surface integrity Ti-6Al-4V alloy 

分 类 号：TG146.23[一般工业技术—材料科学与工程]