A parametric study of improving tool life by electrospark deposition

• Published in: Wear 1990-06, Vol.138 (1-2), p.137-151
• Main Authors: Brown, E.Allen, Sheldon, Gary L., Bayoumi, Abdel E.
• Format: Article
• Language: English
• Subjects: cutting tools; service life
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/0043-1648(90)90173-8

Electrospark alloying (ESA) is a pulsed microwelding surfacing process for alloying a hard wear resistant electrode with a metallic substrate. This process was evaluated as a means of increasing metal cutting tool life in machining operations. A number of ESA electrode material parameters were first screened with a crossed cylinder wear testing machine (ASTM G-83). Full hard high speed steel (HSS) cylinders were run against an ESA-coated stationary HSS cylinder. Three superior coatings from these tests were then applied to the flank and face surfaces of high speed steel tools. Machining test results showed that the dominant wear mode of crater wear was significantly reduced by ESA coating. ESA coating of the tool face only was shown to increase wear resistance significantly more than coating both face and flank surfaces. In addition, programming the electrode motion from side to side rather than front to back over the tool face increased tool life. Comparisons are made with uncoated HSS and TiN-coated (PVD technique) HSS tools. The TiN-coated tool has a similar tool life to failure. The best ESA coated tool had a life better than the HSS tool by roughly 2000%.