Development and Kinetics of TiB2 Layers on the Surface of Titanium Alloy by Superplastic Boronizing

作者：Taazim Nor Taibah; Jauhari Iswadi^*; Miyashita Yukio; Sabri Mohd Faizul Mohd

来源：Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 2016, 47A(5): 2217-2222.

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 degrees C, 950 degrees C, and 1000 degrees C), and it is held for four different boronizing times of 1, 2, 3, and 6 hours. TiB2 is the only boride compound identified after the boronizing process. Boronized layer thickness in the range of 44.9 +/- 1.1 to 149 +/- 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 +/- 0.8) x 10(-13), (4.1 +/- 1.5) x 10(-13), and (8.86 +/- 4.1) x 10(-13) m(2) s(-1), respectively and the values are higher as compared to other works referred. The activation energy obtained for this process is 226.17 +/- 8.3 kJ mol(-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.

• 出版日期2016-5