High-temperature deformation behavior of Ti-TiBw in-situ metal-matrix composites

Abstract

In developing titanium-based materials for high-performance structural applications, the focus has been on discontinuously reinforced titaniummatrix composites that are based on the in-situ creation of TiB whiskers. This article presents the elevated-temperature compressive fl ow properties of Ti-TiB W composites as a function of temperature (from 973 K to 1,273 K), strain rate (from 10 -5 to 10 -3 s -1 ), and the TiB whisker content (commercially pure titanium and composites with 30 to 86 vol.% TiB w ). In both the commercially pure titanium and the TiB-whisker-containing titanium composites, fl ow stress increases with increasing strain rate and decreasing test temperature. In this study, fl ow stress increased with increasing volume fraction of TiB at a given temperature and strain rate. The composite containing 86% TiB w showed significantly higher elevated-temperature strength when compared to the other composites. The composites exhibit systematic trends in the variation of work-hardening behavior (in terms of work-hardening exponent, n, and work-hardening rate, dσ/dε) and the strain-rate dependence.

Mechanical Behavior and Microstructure Evolution of a Ti-15Mo/TiB Titanium–Matrix Composite during Hot Deformation

“…Quite low values of strain rate sensitivity m = 1/n ≈ 0.1-0.2 (Figure 8a) along the obtained values of activation energy suggest the operation of dislocation-related mechanisms, mainly (dislocation glide/climb) during deformation in the studied temperature interval [33,36].…”

Influence of the sintering temperature on the microstructure, mechanical properties and densification characteristics of (TiB + TiC)/TC4 composite

“…The corresponding main deformation mechanism has changed from dislocation slipping mechanism to dislocation climbing mechanism. Therefore, the flow stress of the composite is greatly reduced and the shrinkage is intensified [31].…”

Effect of High-Pressure Torsion on Structure and Microhardness of Ti/TiB Metal–Matrix Composite

“…In this case, high strength and stiffness of ceramic reinforcements combine with good toughness provided by a metal matrix. Some improvements of wear resistance and high temperature properties of MMCs (metal-matrix composites) can also be expected [6,[8][9][10]. Titanium alloys can be reinforced by TiB 2 , TiN, B 4 C, ZrC, TiB, TiC, and Al 2 O 3 [6].…”