Hits:

Indexed by:期刊论文

Date of Publication:2010-08-01

Journal:16th International Symposium on Metastable, Amorphous and Nanostructured Materials

Included Journals:SCIE、EI、CPCI-S、Scopus

Volume:504

Issue:SUPPL. 1

Page Number:S508-S511

ISSN No.:0925-8388

Key Words:Low energy high current pulsed electron beam (LEHCPEB); Melting and heating modes; Craters; Deformed structures; Surface alloying; Surface hardening

Abstract:High current pulsed electron beam is a recently developed technique for surface modification. The pulsed electron irradiation introduces concentrated energy depositions in the thin surface layer of the treated materials, giving rise to an extremely fast heating and subsequent rapid cooling of the surface together with the formation of dynamic stress waves. Improved surface properties (hardness, corrosion resistance) can be obtained under the "melting" mode when the top surface is melted and rapidly solidified (10(7) K/s). In steels, this is essentially the result of nanostructures formed from the highly undercooled melt, melt surface purification, strain hardening induced by the thermal stress waves as well as metastable phase selections in the rapidly solidified melted layers. The use of the "heating" mode is less conventional, combining effects of the heavy deformation and recrystallization/recovery mechanisms. A detailed analysis of a FeAl alloy demonstrates grain size refinement, hardening, solid-state enhanced diffusion and texture modification without modification of the surface geometry. (C) 2010 Elsevier B. V. All rights reserved.