Date of Award

Fall 1992

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Mechanical Engineering - (Ph.D.)

Department

Mechanical Engineering

First Advisor

Roman Dubrovsky

Second Advisor

Rong-Yaw Chen

Third Advisor

John Vincent Droughton

Fourth Advisor

Nouri Levy

Fifth Advisor

Lawrence Suchow

Abstract

In this work a newly developed surface treatment process, Magneto-Plasma Ion Nitriding process, was developed and studied. This process was developed to increase durability and wear resistance of operational surfaces of different machine components.

In this study, orthogonal experimental analysis was used to develop, optimize, and select the process parameters. Coating layers were characterized and studied by using scanning electron microscopy(SEM), Auger electron spectroscopy(AES), and image analysis system. The influence of different process treatment parameters, such as temperature, nitrogen concentration, and magnetization, on the layers properties was studied. The mechanism of layer formation and bonding was proposed and a mathematical model was derived. To perform the wear resistance test, the wear testing methodology and a computer-controlled wear testing machine were designed, manufactured, and assembled.

Selected process parameters permitted developing different types of compound layers, such as ε , γ1, α phases, or their combination. Microstructure and microhardness investigations were performed with respect to deposited layers.

Differently applied magnetic treatments to the surface provided improvement in diffusion bonding of deposited compound layers to substrate. The mechanism of this bonding was introduced and explained in this work.

As a result of the developed magneto-plasma ion nitriding surface treating process, it was found that durability and wear resistance of operational surfaces of machine components made from different steels have been significantly improved.

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