Development and Kinetics of TiB sub(2) Layers on the Surface of Titanium Alloy by Superplastic Boronizing

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 47; no. 5; pp. 2217 - 2222
• Main Authors: Taazim, Nor Taibah, Jauhari, Iswadi, Miyashita, Yukio, Sabri, Mohd Faizul Mohd
• Format: Journal Article
• Language: English
• Published: 01-05-2016
• Subjects: Borides; Boronizing; Intermetallic compounds; Plastic deformation; Superplastic deformation; Superplastic forming; Superplasticity; Titanium base alloys; Titanium diboride
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-016-3359-0

The aim of this work is to explore the possibility of combining boronizing and superplastic deformation on titanium alloy (Ti6Al4V) substrate. Superplastic boronizing (SPB) is carried out at three different temperatures of 1173 K, 1223 K, and 1273 K (900 degree C, 950 degree C, and 1000 degree C), and it is held for four different boronizing times of 1, 2, 3, and 6 hours. TiB sub(2) is the only boride compound identified after the boronizing process. Boronized layer thickness in the range of 44.9 plus or minus 1.1 to 149 plus or minus 1 mu m is formed on the surface of Ti6Al4V and the surface hardness values increase with respect of the formation's degree of the hard boronized layer. Diffusion coefficient values attained for all temperatures are (1.44 plus or minus 0.8) 10 super(-13), (4.1 plus or minus 1.5) 10 super(-13), and (8.86 plus or minus 4.1) 10 super(-13) m super(2) s super(-1), respectively and the values are higher as compared to other works referred. The activation energy obtained for this process is 226.17 plus or minus 8.3 kJ mol super(-1). The results obtained suggest that the SPB process provides a more competent and efficient process for the formation of a boronized layer on the alloy.