The effect of laser treatment parameters on temperature distribution and thickness of laser-alloyed layers produced on Nimonic 80A-alloy

Abstract

Purpose: The aim of this paper was to determine the influence of laser treatment parameters on temperature distribution and thickness of laser-alloyed layers produced on Nimonic 80A-alloy. Design/methodology/approach: In this paper laser alloying was used in order to produce layers on Nimonic 80A-alloy surface. The three types of the alloying materials were applied: B, B+Nb and B+Mo. Microstructure observations were carried out using an optical microscope. The hardness measurements were performed using a Vickers method under a load of 0.981 N. For evaluation of temperature distribution the equations developed by Ashby and Esterling were used. Findings: The produced layers consisted of re-melted zone only and were characterized by high hardness (up to 1431 HV0.1). The increase in laser beam power caused an increase in thickness and decrease in hardness of re-melted zones. The temperature distribution was strongly dependent on laser treatment parameters and physical properties of alloying material. The higher laser beam power, used during laser alloying with boron, caused an increase in layer thickness and temperature on the treated surface. The addition of Mo or Nb for alloying paste caused changes in melting conditions. Research limitations/implications: The obtained results confirmed that laser beam power used for laser alloying influenced the thickness and hardness of the produced layers. Moreover, the role of type of alloying material and its thermal properties on melting condition was confirmed. Practical implications: Laser alloying is the promising method which can be used in order to form very thick and hard layers on the surface of Ni-base alloys. The obtained microstructure, thickness and properties strongly dependent on laser processing parameters such as laser beam diameter, laser beam power, scanning rate as well as on the type of alloying material and its thickness, or type of substrate material. Originality/value: In this paper the influence of alloying material on temperature distribution, thickness and hardness of the laser-alloyed layers was in details analyzed.