Synthesis and multiple hardening of a rapidly solidified iron-based matrix

Abstract

The sintering of Fe-Cu and Fe-Cu-Ni3Al powder compacts by laser beam was studied to determine densification, microstructural development, and microhardness before and after thermo-mechanical treatments. Laser sintering (LS) was conducted using pulsed Nd:YAG laser, and optimum parameters of pulse energy, pulse length, pulse frequency, scanning speed, hatch spacing, and layer thickness were determined. Also, the effects of solidification rate, cold deformation (10%), and the addition of complex intermetallic Ni3Al (Fe, Ti, B) on microhardness were analyzed before and after the aging process. It was concluded that rapidly solidified structure, as well as the presence of Ni3Al particles and metastable CuFe phase, which are a product of laser sintering, affected a higher degree of iron matrix hardening which was retained up to high temperatures. Originality of investigations presented in this paper is in the employment of laser for synthesis of Fe-Cu-Ni3Al alloy, which was not discussed in the literature so far. Realization of this complex synthesis required consideration and adaptation of the laser sintering method which has been successfully applied for other types of alloys.