|
3851 |
|
Friday, May 23, 2014, Hall H3 2:20 PM Medical Industry 2 / Metal Coatings |
|
Effects of Al content and addition of third element on fabrication of Ti-Al intermetallic coatings by heat treatment of warm sprayed precursor |
|
Judyta Sienkiewicz* / National Institute for Materials Science, Japan Seiji Kuroda/ NIMS, Japan Hideyuki Murakami/ NIMS, Japan Hiroshi Araki/ NIMS, Japan Krzysztof Kurzydlowski/ WUT, Poland |
|
Warm Spraying is an atmospheric coating process based on high-velocity impact bonding of powder particles. By decreasing the temperature of combustion gas through mixing nitrogen with the combustion gas, the oxidation of feedstock powder can be significantly controlled compared with conventional thermal spraying. This advantage is particularly important for Ti-based coating materials, which rapidly oxidize in elevated temperatures. In this study, mixtures of titanium and aluminum powder with 50:50, 40:60, 30:70, 20:80 atomic ratio were prepared for the Warm Spray process. The transformation of the as-sprayed deposits into an intermetallic structure was carried out during heat treatment. The microstructure, chemical and phases composition of the deposited and the heat treated coatings were characterized by using SEM, EDS and XRD. It was found that the Al content can affect on the thickness expansion of heat treated Ti-Al coatings significantly and can also have a major influence on the porosity development which is caused by Kirkendall effect. The effect of third element addition and pressure during heat treatment to produce dense Ti-Al intermetallic coating were also examined. |