Date of Award

1-28-2019

Publication Type

Master Thesis

Degree Name

M.A.Sc.

Department

Mechanical, Automotive, and Materials Engineering

Supervisor

J. Urbanic

Rights

info:eu-repo/semantics/openAccess

Abstract

Laser cladding offers some distinct advantages for surface modifications, and is one of the direct energy deposition processes used for metal additive manufacturing. In this study, the effect of variations in the percentage of bead overlap was studied for 6 different scenarios. The overlap percentage varied from 30 % to 47 % along the length of the beads. The temperature evolution and melt pool depth as well as the hardness and distortion fields were studied using experimental and numerical methods. A three-dimensional (3D) transient uncoupled thermo-elastic–plastic model was generated to simulate a thermal process, hardness and distortion for the single track and multi-track laser cladding models. The latent heat and phase transformations effects were considered in the thermal analysis. The numerical results were validated by experimentally-measured values. To identify the effects of the length of the clad beads on hardness and distortion, a sensitivity analysis was performed for a set of single track and multi-track clad beads where the bead length was doubled. The experimental data values were collected by measuring the clad hardness (Vickers hardness testing). and a height gage was used to measure distortion of the base plates before and after the experimental runs. The studies indicate that the overlap percentage affects the hardness, but not distortion. The hardness in the multi-track models reduces when the overlap percentage increases. It has revealed that the depth of the melt pool has a reverse relation with hardness. Additional studies must be performed, as many parameters, including the tool path, influence the quality and performance characteristics.

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