A comparative study of surface integrity of Ti–6Al–4V alloy machined by EDM and AECG

Abstract The electrical discharge machining (EDM) process produces the recast layer with or without cracks on the surface that requires a remedial post-treatment in the manufacture of critical or highly stressed surfaces. One of the frequently used post-treatment processes is also the abrasive electrochemical grinding (AECG) and it has been widely used in the precision machining of difficult-to-cut materials due to an enhanced surface integrity and productivity. The aim of this study is to investigate improvability of surface integrity in terms of machining voltage, electrolyte flow rate and table feed rate parameters of AECG in EDMed Ti6Al4V alloy. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrograph (EDS) and surface roughness measurement were performed to study the surface characteristics of the machined samples. Experimental results indicate that the AECG process effectively improves the surface roughness and eliminates the EDM damages completely by setting suitable grinding parameters.

[1]  S. Zaborski,et al.  Wear of cathode in abrasive electrochemical grinding of hardly machined materials , 2004 .

[2]  Madhav Datta,et al.  Electrochemical machining under pulsed current conditions , 1981 .

[3]  B. Bhattacharyya,et al.  Experimental study on electrochemical micromachining , 2005 .

[4]  Z. M. Wang,et al.  Titanium alloys and their machinability—a review , 1997 .

[5]  Werner Theisen,et al.  Electro discharge machining of nickel–titanium shape memory alloys , 2004 .

[6]  J. Schultze,et al.  Electrochemical machining of the steel 100Cr6 in aqueous NaCl and NaNO3 solutions: microstructure of surface films formed by carbides , 2001 .

[7]  Salvador Bracho,et al.  Current mode controlled LCC resonant converter for electrical discharge machining applications , 2000, ISIE'2000. Proceedings of the 2000 IEEE International Symposium on Industrial Electronics (Cat. No.00TH8543).

[8]  Yan Cherng Lin,et al.  Surface Improvement Using a Combination of Electrical Discharge Machining with Ball Burnish Machining Based on the Taguchi Method , 2001 .

[9]  Madhav Datta,et al.  Anodic dissolution of metals at high rates , 1993, IBM J. Res. Dev..

[10]  J. Kozak,et al.  Selected problems of abrasive hybrid machining , 2001 .

[11]  Liam Blunt,et al.  3D surface characterisation of electropolished EDMed surface and quantitative assessment of process variables using Taguchi Methodology , 2002 .

[12]  A. Jawaid,et al.  The effect of machining on surface integrity of titanium alloy Ti–6% Al–4% V , 2005 .

[13]  B. Yan,et al.  The effect in EDM of a dielectric of a urea solution in water on modifying the surface of titanium , 2005 .