High Strength and High Wear‐Resistant Ti Composites Fabricated by Powder Metallurgy Pressureless Sintering

Abstract

In this work, high strength and high wear‐resistant titanium matrix composites (TMCs) reinforced with in situ TiC derived from pyrolysis of polysilazane (PSZ) are fabricated successfully. The processing technology is developed with a novel powder metallurgy method combining solution‐assisted wet mixing and pressureless sintering. The effects of PSZ addition on the microstructure, hardness, mechanical properties, and tribological properties are systematically studied. The TMCs possess better comprehensive properties compared to conventional ex situ methods. The pyrolysis of PSZ leads to the formation of TiC particles and N, Si atoms solid‐solution in the Ti matrix. The microstructure of the composites is homogenous and fine‐grained. The average grain size of α‐Ti decreases significantly from 106.1 µm of pure Ti to 37.2 µm of the 1.5 wt% PSZ/Ti composite. Among these TMCs, the 1.5 wt% PSZ/Ti composite displays comprehensively excellent mechanical properties with the ultimate tensile strength (UTS) of 711 MPa, yield strength (YS) of 568 MPa, and elongation (EL) of 8.0%. In addition, the composite possesses a high wear resistance with a low specific wear rate of 0.355 × 10−12 m3 N−1 m−1 under constant condition (0.03 m s−1, 2N).

Experimental Study on the Comparison between Network Microstructure Titanium Matrix Composites and Ti6Al4V on EDM Milling

“…With the ongoing development of metal matrix composites, titanium-based composites have emerged as a promising material, boasting high strength, excellent ductility, remarkable wear resistance, and superior high-temperature durability. These exceptional properties have led to their widespread application in aerospace and advanced military fields [1][2][3]. Unfortunately, research has revealed that the majority of titanium matrix composites currently feature a uniform distribution of reinforcement within the matrix material, leading to subpar mechanical properties and serious ambient temperature brittleness [4].…”