Research on Surface Modification Technique by EDM

2010 ◽  
Vol 154-155 ◽  
pp. 1193-1198 ◽  
Author(s):  
Xiao Hai Li ◽  
Yu Fang ◽  
Xin Rong Wang ◽  
Bao Lin Yin

This paper describes a new method of die surface modification by ordinary Electrical Discharge Machining (EDM) tool. First, the principle of this method is studied. Secondly, the technology and characteristics of the die steel coating are discussed in detail based on lots of experiments, and the results show that the die steel characteristics are improved evidently by using EDM. At last, the technology is applied to the punch die initially, and it can be drawn that the life of the coated punch die is improved evidently compared with the non-coated punch die through the punching test.

2012 ◽  
Vol 490-495 ◽  
pp. 2619-2623 ◽  
Author(s):  
Xiao Hai Li ◽  
De Cheng Wang ◽  
Yu Fang

A new method of die surface modification by ordinary Electrical Discharge Machining (EDM) is described. First, the surface modification mechanism by EDM is studied, which is different with ordinary EDM. Secondly, the influence of important electric parameters on the effect of electric discharging coating in working fluid is analyzed, which is helpful to improve the coating layer. At last, the new type special pulse power supply with additional pulse current is designed. The special pulse power supply for electrical discharge coating behaves well, and the compacted coating layer without cracks deposited on the surface of die by EDM can be obtained, which can prolong the life of die


Author(s):  
S Kumar ◽  
R Singh ◽  
T P Singh ◽  
B L Sethi

The electrical discharge machining (EDM) process is extensively used in the tool and die making industry for accurate machining of internal profiles in hardened materials. Although it is essentially a material removal process, efforts have been made in the recent past to use it as surface treatment method. This article investigates and compares the effect of material transfer from electrode bodies (copper, copper—chromium, and copper—tungsten) and tungsten powder suspended in the dielectric medium during die-sinking EDM of AISI H13 die steel. Results show a 76 per cent increase in micro-hardness by machining with a copper—tungsten electrode and a 111 per cent increase by machining with tungsten powder mixed in the dielectric. The copper—chromium electrode gives the best surface roughness (Ra) value of 2.67 μ m. Scanning electron microscopy and X-ray diffraction analysis of the machined surfaces show alloying of parent material with tungsten and tungsten carbide. Chemical composition of the machined surfaces was further checked on an optical emission spectrometer to verify the results. Besides a significant presence of tungsten, an increase in the percentage of carbon is also observed.


Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1018
Author(s):  
Ziliang Zhu ◽  
Dengji Guo ◽  
Jiao Xu ◽  
Jianjun Lin ◽  
Jianguo Lei ◽  
...  

Titanium-nickel shape memory alloy (SMA) has good biomedical application value as an implant. Alloy corrosion will promote the release of toxic nickel ions and cause allergies and poisoning of cells and tissues. With this background, surface modification of TiNi SMAs using TiC-powder-assisted micro-electrical discharge machining (EDM) was proposed. This aims to explore the effect of the electrical discharge machining (EDM) parameters and TiC powder concentration on the machining properties and surface characteristics of the TiNi SMA. It was found that the material removal rate (MRR), surface roughness, and thickness of the recast layer increased with an increase in the discharge energy. TiC powder’s addition had a positive effect on increasing the electro-discharge frequency and MRR, reducing the surface roughness, and the maximum MRR and the minimum surface roughness occurred at a mixed powder concentration of 5 g/L. Moreover, the recast layer had good adhesion and high hardness due to metallurgical bonding. XRD analysis found that the machined surface contains CuO2, TiO2, and TiC phases, contributing to an increase in the surface microhardness from 258.5 to 438.7 HV, which could be beneficial for wear resistance in biomedical orthodontic applications.


2001 ◽  
Vol 67 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Toshio MORO ◽  
Akihiro GOTO ◽  
Naotake MOHRI ◽  
Nagao SAITO ◽  
Koei MATSUKAWA ◽  
...  

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