Surface Alloying of Nanocrystalline Fe-0.45 wt Pct C Alloy Subjected to Surface Mechanical Attrition Treatment Within Cr Powders

Abstract

A Fe-0.45 wt% C alloy plate was subjected to surface mechanical attrition treatment (SMAT) in a camber filled with Cr powder and a nanocrystalline surface layer containing Cr element was produced during the treatment. Owing to the high diffusivity of nanocrystalline surface layer, Cr element can diffuse and be pressed into nanocrystalline surface layer during SMAT. Within the subsequent annealing process, Cr element can further diffuse in the surface layer, resulting in formation of new compounds, such as (Cr,Fe)₂₃C₆ and (Cr,Fe)₇C₃. SMAT within metallic powder, which can conveniently and effectively accomplish surface modification, should be concerned and utilized.

Keywords:

• Surface mechanical attrition treatment
• nanocrystalline materials
• diffusion
• surface alloying
• microstructure

Acknowledgment

The present work was financially supported by “Chen Guang” project under Grant No. 09CG51 sponsored by Shanghai municipal education commission and Shanghai education development foundation, “Selection and Training the Excellent Young College Teacher” project under Grant No. slg09015 and “Shanghai Leading Academic Discipline Project” under Grant No. J50503 sponsored by Shanghai municipal education commission.