Production of Compositionally Gradient Coatings by Laser Spraying : Properties of Ti-TiN sprayed Coatings for Repeated Thermal Shock

• Published in: Transactions of the Japan Society of Mechanical Engineers Series C Vol. 58; no. 554; pp. 3069 - 3074
• Main Authors: KATSUMURA, Munehide, MATSUDA, Jun, MIYOSHI, Yoh, UKAI, Momokazu, UTSUMI, Akihiro, YONEDA, Masafumi
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Mechanical Engineers 1992
• Subjects: Laser, Spraying, Coating, Thermal Shock, Titanium, Titanium Nitride, Compositionally Gradient Coatings, Thermal Barrier Coatings
• ISSN: 0387-5024; 1884-8354
• DOI: 10.1299/kikaic.58.3069

Compositionally gradient coatings for thermal shock have been developed by a laser spraying method. They consist of titanium and titanium nitride. A pure titanium wire was melted by a high-energy-density carbon dioxide laser beam. An argon stream produced a fine spray of melted titanium particles which coated a mild steel substrate (60 x 60 x 4.5 mm) . The next layer was a mixture of titanium and titanium nitride which was formed by the mixed gas of argon and nitrogen. The last layer was coated with nitrogen only. The chemical components of each layer were graded through the coatings (about 1 mm thick). They were heated to 2000 K by a laser beam whose diameter and power density were about 42 mm and 290 W/cm2, respectively, and cooled to room temperature in water. As a result of the repeating thermal shock test, it was found that these laser-sprayed coatings are excellent as thermal barrier coatings.