Session: 03-08-03: Computational Modeling and Simulation for Advanced Manufacturing

Paper Number: 145902

145902 - Investigating the Impact of Pvd Process Parameters on Residual Stress Distribution: A Multi-Scale Numerical Analysis Approach 

The reliability and performance of coatings in structural, mechanical, and tribological applications are closely linked to deposition process parameters. It is crucial to carefully select these parameters to achieve desired coating characteristics. The distribution of stress within a coating is complex and can vary throughout its thickness. Thin coating systems often exhibit significant stress gradients between the coating and the underlying substrate. Residual stress in thin PVD coatings arises from a combination of growth stress and thermal stress. During the cooling process from the deposition temperature to room temperature (RT), thin coatings deposited via PVD undergo substantial thermal stresses. Despite the lower processing temperature, thermal mismatch stresses can be significant due to variations in physio-thermal properties between the coating and substrate materials, especially when there are substantial disparities in elastic properties and coefficients of thermal expansion. These stresses can lead to various failure modes, directly affecting the reliability and durability of the coated system.

Understanding the underlying physics of the deposition process and resulting stresses, particularly thermal stresses within the coating-substrate system, is paramount. Key physical parameters of both the coating and the substrate, such as coefficient of thermal expansion (CTE) and elastic modulus, significantly influence thermal stresses. Typically, thermal stresses primarily occur at the interfacial contact between the coating-substrate system. Therefore, residual stresses in PVD coatings cannot be solely attributed to growth. Effective stress management is critical in coating manufacturing, and accurate estimation of stress is increasingly important for ensuring the integrity of the coating-substrate system. There is a demand for a comprehensive methodology in thermo-mechanical design, specifically for layered coatings, that should complement experimental procedures used to evaluate coating performance. Although analytical models can handle linear-elastic or simple elastic-plastic materials for thermal stress prediction, numerical techniques such as finite element analysis (FEA) can address more general 2D or 3D problems in simulating thermal stresses within coating-substrate systems.

This study employs a multi-scale numerical approach to estimate the residual stress distribution within the coating-substrate system. Validation of the numerical model is conducted against experimental findings concerning a TiB2 - Tungsten Carbide coating-substrate configuration. Experimental assessments entail micro-scratch tests, multi-pass wear tests, and toughness measurements conducted via an Anton Paar-RST3 Revetest® Scratch Tester in Buchs, Switzerland. Micro-scratch tests aim to evaluate coating behavior under incremental loading. Residual stress calculations in the coatings are facilitated by a Proto LXRD Stress Analyzer (Proto Manufacturing Limited, LaSalle, ON, Canada) utilizing the sin2 Ψ method. Measurements involve multiple exposures at 11 Ψ tilts, employing a 2.0 mm round aperture with an 80 s collection time per diffraction peak. Ti-Kα radiation (2.7497 Angstroms) is utilized on the (101) plane at a diffraction angle of approximately 84°. Gaussian function fitting is applied for diffraction peak analysis. The validated model is then utilized to explore the influence of process parameters on residual stress distribution across various coating-substrate systems and its implications on coating adhesion.

Presenting Author: Abul Fazal M Arif King Fahd University of Petroleum and Minerals

Presenting Author Biography: DR. Abul Fazal Arif is a full professor in the mechanical engineering department at King Fahd University of Petroleum and Minerals (KFUPM), Saudi Arabia, a highly reputed educational institution. His teaching and research background are related to the following areas: Solid mechanics and applied materials; and Mechanical design and manufacturing.
He received PhD and MS degrees in Mechanical Engineering from the University of Minnesota, Minneapolis, USA, in 1991 and 1988, respectively. Before joining academia as a faculty member in 1996, he worked for five years in the industry, acquiring practical experience related to design and development. Dr. Arif has more than 25 years of experience in teaching, research, curriculum design, new program development, program assessment, accreditation, student advising, and lab development.

Authors:

Shazia Gul Jan King Fahd University of Petroleum and Minerals
Abba Abdulhamid Abubakar King Fahd University of Petroleum and Minerals
Abul Fazal M Arif King Fahd University of Petroleum and Minerals
Mohammad Shariful Islam Chowdhury McMaster University
Syed Sohail Akhtar King Fahd University of Petroleum and Minerals
Bipasha Bose McMaster University
Khaled Al-Athel King Fahd University of Petroleum and Minerals