학술논문

On the heat-treatment induced evolution of residual stress and remarkable enhancement of adhesion strength of cold sprayed Ti–6Al–4V coatings
Document Type
article
Source
Results in Materials, Vol 7, Iss , Pp 100119- (2020)
Subject
Cold spray
Ti–6Al–4V
Residual stress
Heat treatment
Martensite
Adhesion strength
Materials of engineering and construction. Mechanics of materials
TA401-492
Language
English
ISSN
2590-048X
Abstract
Cold spraying is an extremely viable repair technique for high-value aerospace components made of Ti–6Al–4V alloys. However, significant residual stresses are generated in as-sprayed coatings and it is desirable to relieve such stresses as they could impact coating adherence and subsequent performance. We have used a series of post heat treatments to identify the most suitable one for stress-relieving of cold sprayed Ti–6Al–4V coatings on Ti–6Al–4V substrates. The alleviation of macroscopic residual stresses is accompanied by changes in coating microstructures, which has also been discussed. Post heat treatment particularly at 600 and 950 ​°C results in a significant increase in the interfacial bond strength compared to as-sprayed coating. Reduction in coating porosity and increased fraction of adhered powder particles to the substrate are also attributed to the increase in coating adhesion strength.