Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 08, 2016 - October 10, 2016
In order to investigate the fundamental process of residual stress development in thermal barrier coating during thermal spray, a model experiment is conducted using a paraffin wax. The melted paraffin wax was dropped onto a circular substrate of type 430 stainless steel, and the strain and temperature were measured on the back surface of substrate. Measured strain includes the thermal strains caused by the difference of linear expansion coefficient between substrate and strain gauge, as well as induced by temperature distribution in the circular substrate. These strains were compensated from the measured strain and temperature distribution in the substrate. The compensated strain at the substrate back surface was tensile when the paraffin wax was dropped and solidified. The tensile strain was increased with the number of the droplets and three or four droplets resulted in de-bonding of the solidified wax layer. The strain was converted into the stress in the coating using FEM. It was revealed that the radial component of the stress in the coating was 10-20 MPa in tension.
