Laser surface treatment of high‐speed tool steel (AISI M2)

Abstract

High‐speed tool steel (AISI M2) surface is pre‐prepared to form a thin carbon film containing 5% B4C particles prior to laser treatment process. Morphological and metallurgical changes are examined in the treated layer using electron microscope, energy dispersive spectroscopy, and X‐ray diffraction. The microhardness and the residual stress formed at the treated surfaces are measured for samples with and without B4C particles. It is found that the micro‐stresses formed in the neighborhood of B4C particles at the treated surface contributed to the microhardness enhancement at the surface. This is associated with the mismatch of thermal expansion coefficients between B4C particles and the base alloy. The nitride phases are formed at the treated surface, which also contribute to the microhardness increase at the surface. Copyright © 2012 John Wiley & Sons, Ltd.

Quantitative Evaluation of the Effectiveness of Laser Surface Modification Technologies

“…The fact of the parallel action of convective and thermodiffusion mass transfer under laser radiation is shown in papers [5][6][7]. It is a certain obstacle to get a stable uniform alloyed layer: the first mechanism leads to a significant inhomogeneity of the melting bath, the second mechanism -to a continuous resorption of the convective flows of alloying elements.…”

Archives of Metallurgy and Materials

“…Enhanced wear resistance and thermal fatigue resistance is achieved by creating a chemically homogenous, fine-crystalline surface layer without altering the chemical composition of the material. Even more advantageous effects, such as improved functional properties, are achievable by alloying a material surface layer with the particles of hard phases of carbides, oxides or nitrides [7][8]. Studies in the field of laser remelting, alloying and hardfacing conducted at home and abroad are focussed on the treatment of high-speed steels and machine steels by means of continuous and pulsed CO 2 gas lasers and solid-state lasers.…”

“…Studies in the field of laser remelting, alloying and hardfacing conducted at home and abroad are focussed on the treatment of high-speed steels and machine steels by means of continuous and pulsed CO 2 gas lasers and solid-state lasers. High power diode lasers, allowing to further develop and considerably expand the use of surface engineering technologies, have been introduced in industry due to the sharp advancement of laser techniques and devices [4,7]. The investigation results obtained may be used for the further research on optimization of the surface layer properties of the tool steels, targeted at obtaining tools with the possibly high mechanical and service properties.…”