Correlation of microstructure with hardness and wear resistance of surface composites fabricated by high-energy electron beam irradiation of Fe-based metamorphic powders

Abstract

In this study, surface composites were fabricated with Fe-based metamorphic powders by high-energy electron beam irradiation, and the correlation of their microstructure with hardness and wear resistance was investigated. Fe-based metamorphic powders were deposited on a plain carbon steel substrate, and then electron beam was irradiated on these powders without flux to fabricate a one-layered surface composite. A two-layered surface composite was also fabricated by irradiating electron beam again onto the powders deposited on the one-layered surface composite. The composite layers of 1.3;1.9 mm in thickness were homogeneously formed without defects and contained a large amount (up to 48 vol pct) of hard and fine Cr 2 B crystalline phases in the Cr 0.19 Fe 0.7 Ni 0.11 matrix. Since the hardness and wear resistance of the surface composite layers were directly influenced by hard Cr 2 B phases, they were two to three times greater than those of the steel substrate. In particular, the twolayered surface composite showed a high hardness of ;300 VHN even at 750°C, as well as at room temperature, because Cr 2 B phases and the Cr 0.19 Fe 0.7 Ni 0.11 matrix were hard and thermally stable.

Correlation of Microstructure, Hardness, and Fracture Toughness of Fe-Based Surface Composites Fabricated by High-Energy Electron Beam Irradiation with Fe-Based Metamorphic Alloy Powders and VC Powders

“…Metamorphic powders contain a considerable amount of amorphous phases in a powder state, but thermal sprayed coatings or surface composites fabricated with them consist of crystalline phases, because the amorphous phases are crystallized. [21,22] These powders were mixed with VC powders obtained from CERAC, Inc. (Milwaukee, WI) in order to additionally improve properties. The VC powders have high hardness (approximately 2900 Vickers hardness (VHN)), excellent thermal and wear resistance, a high melting point (2700°C), and a density of 5.71 g/cm 3 .…”

Performance of a cutting tool made of steel matrix surface nano-composite produced by in situ laser melt injection technology

“…This method has been developed further by using reaction casting by Feng et al (2005) and high-energy electron beam irradiation by Lee et al (2006). The method was extended to produce Fe/(TiW)C composite powder by Correa et al (2007).…”