Surface Modification of High-Speed Tool Steel by Repeated Irradiations of Intense Pulsed Ion Beam

• Published in: Japanese Journal of Applied Physics Vol. 40; no. 2S; p. 1083
• Main Authors: Hiroshi Akamatsu, Hiroshi Akamatsu, Yoshisuke Tanihara, Yoshisuke Tanihara, Tsutomu Ikeda, Tsutomu Ikeda, Kingo Azuma, Kingo Azuma, Etsuo Fujiwara, Etsuo Fujiwara, Mitsuyasu Yatsuzuka, Mitsuyasu Yatsuzuka
• Format: Journal Article
• Language: English
• Published: 01.02.2001
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.40.1083

Surface modification of a high-speed tool steel (SKH51) has been performed by irradiation of the proton intense pulsed ion beam (IPIB) with the ion energy of 180 keV, the ion current density of 460 A/cm 2 , and pulse duration of 65 ns. By 1-pulse irradiation of the IPIB, the second phase carbides such as VC, Fe 6 C, and Cr 6 C are dispersed from the irradiated surface, and the average grain size decreases to 240 nm corresponding to approximately 1/30 of the untreated one. Repeated irradiations of the IPIB result in the reduction in grain size and conversion of an α-Fe structure to a γ-Fe one. The SKH51 treated by 10-pulses irradiation has a single phase of γ-Fe, and the grain size is reduced to approximately 1/170 of that of the untreated one. In addition, the 10-pulses-irradiated surface has an improved wear resistance.