Surface preparation of powder metallurgical tool steels by means of wire electrical discharge machining
Artikel i vetenskaplig tidskrift, 2012

The surface of two types of powder metallurgical (PM) tool steels (i.e., with and without nitrogen) was prepared using wire electrical discharge machining (WEDM). From each grade of tool steel, seven surfaces corresponding to one to seven passes of WEDM were prepared. The WEDM process was carried out using a brass wire as electrode and deionized water as dielectric. After eachWEDM pass the surface of the tool steels was thoroughly examined. Surface residual stresses were measured by the X-ray diffraction (XRD) technique. The measured stresses were found to be of tensile nature. The surface roughness of the WEDM specimens was measured using interference microscopy. The surface roughness as well as the residual stress measurements indicated an insignificant improvement of these parameters after four passes of WEDM. In addition, the formed recast layer was characterized by means of scanning electron microscopy (SEM), XRD, and X-ray photoelectron spectroscopy (XPS). The characterization investigation clearly shows diffusion of copper and zinc from the wire electrode into the work material, even after the final WEDM step. Finally, the importance of eliminating excessive WEDM steps is thoroughly discussed.

Microstructure

Steel

Wire Electric Discharge Machining (WEDM)

Residual stresses

Författare

Sepehr Hatami

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Mehrdad Shahabi Navid

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Lars Nyborg

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

1073-5623 (ISSN)

Vol. 43 9 3215-3226

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Styrkeområden

Materialvetenskap

DOI

10.1007/s11661-012-1137-1