High Temperature Deformation Behavior of In-Situ Synthesized Titanium-Based Composite Reinforced with Ultra-Fine TiB Whiskers.

Rongjun Xu,Bin Liu,Wenmin Guo,Yan Nie,Yuankui Cao,Shifeng Liu,Yong Liu

doi:10.3390/ma11101863

Abstract

A TiB/Ti-6Al-4V composite reinforced with ultra-fine TiB whiskers (UF-TiB) was prepared by the powder metallurgy method. High temperature compression tests were carried out to study the hot deformation behavior of the UF-TiB/Ti-6Al-4V composite. The compressive deformation was performed in the temperature range of 900–1200 °C and the strain rate range of 0.001–10 s−1. The results showed that stable flow occurred at the condition of 900–1200 °C/0.001–0.01 s−1. The optimum working condition was 900 °C/0.001 s−1, with the deformation mechanism of dynamic recrystallization (DRX). Instable flow occurred when the strain rate was higher than 0.01 s−1, where the failure modes included adiabatic shear deformation, whisker breakage and whisker/matrix debonding. The deformability of the UF-TiB/Ti-6Al-4V composite was much better than the traditional casted and the pressed + sintered TiB/Ti-6Al-4V composites, which are typically reinforced with coarse-grained TiB whiskers. The high deformability was primarily attributed to the ultra-fine reinforcements, which could coordinate the deformation more effectively. In addition, a fine matrix microstructure also had a positive effect on deformability because the fine matrix microstructure could improve the grain boundary sliding.

Highlights

Titanium alloy reinforced with fibers or particles, known as titanium matrix composites (TMCs) are commonly used in aerospace and marine industries that require their high specific strength and good corrosion resistance [1,2,3]
Many researchers have studied the hot deformation behavior of titanium alloys reinforced with titanium boride (TiB) whiskers
TiB/Ti-6Al-4V composite reinforced with ultra-fine TiB whiskers was prepared by the spark plasma sintering (SPS) method and the hot deformation behavior of UF-TiB/Ti-6Al-4V composite was studied

Summary

Introduction

Titanium alloy reinforced with fibers or particles, known as titanium matrix composites (TMCs) are commonly used in aerospace and marine industries that require their high specific strength and good corrosion resistance [1,2,3]. The titanium boride (TiB) whisker is an effective reinforcement for titanium alloys, since the ceramic TiB phase has a high strength and an excellent thermal stability. Previous studies have indicated that the mechanical performances of titanium alloy are significantly enhanced with the addition of TiB whiskers [5,6]. Hot deformation is an indispensable step for the manufacturing process, and an efficient method to control and enhance the mechanical properties of TMCs [7]. Many researchers have studied the hot deformation behavior of titanium alloys reinforced with TiB whiskers. Cortazar et al [9] investigated the effect of TiB on deformability of the

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Conclusion