Microstructure and Adhesion Strength of Ni3Ti Coating Prepared by Mechanical Alloying and HVOF

• Published in: Physics of metals and metallography 2018-05, Vol.119 (5), p.462-468
• Main Authors: Reddy, Nagaraja C., Ajay Kumar, B. S., Ramesh, M. R., Koppad, Praveennath G.
• Format: Article
• Language: English
• Subjects: Adhesion tests; Adhesive bonding; Adhesive strength; Alloy development; Ball milling; Bond strength; Bonding strength; Chemistry and Materials Science; Diffusion; Flame spraying; Intermetallic compounds; Materials Science; Mechanical alloying; Metallic Materials; Oxy-fuel; Phase Transformations; Porosity; Scanning electron microscopy; Structure; X-ray diffraction
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X18050113

In the present work we report the development of Ni 3 Ti intermetallic compound by high energy ball milling of Ni and Ti powders. The ball milled powders were taken at various intervals (4, 6, 8, 10, and 11 h) to analyze the formation of Ni x Ti x intermetallic compounds. The ball milled powders were analyzed using scanning electron microscopy and X-ray diffraction. The layered shaped powder particles of Ni 3 Ti phase were formed after 11 h of ball milling, which was confirmed by X-ray peaks. Further High-Velocity Oxy-Fuel (HVOF) process was used to coat Ni 3 Ti and Ni 3 Ti + (Cr 3 C 2 + 20NiCr) on MDN 420 steel. Both the coated materials displayed excellent cohesion with minimal porosity less than 2%. The tensile adhesion strength test was carried out on these coatings to check the bond strength. Out of the two the Ni 3 Ti coating showed excellent bond strength of 41.04 MPa compared to that of Ni 3 Ti + (Cr 3 C 2 + 20NiCr) coating.