Microstructures and mechanical properties of in situ TiC–β–Ti–Nb composites with ultrafine grains fabricated by high-pressure sintering

Abstract

In this study, an in situ β–Ti–Nb composites reinforced with TiC particles with an ultrafine grain size were fabricated using a powder metallurgical (PM) method. The microstructures and mechanical properties of the composites were characterized using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and compression tests. TiC particles were formed in the ball-milled powders after annealing at 600 °C due to a chemical reaction between stearic acid and titanium. Using high-pressure sintering (HPS) on an apparatus with six tungsten carbide anvils, a fully dense β–Ti–Nb composite reinforced with fine in situ TiC particles was obtained. The TiC particles exhibit particle sizes of ~500 nm, uniformly distributed in the composite matrix, which had grain sizes of ~600 nm. Thus, the TiC–β–Ti–Nb composite show very high compression yield strength and relatively high plasticity contributed by grain refinement and TiC particles strengthening. The composite with 45 vol.% TiC exhibited excellent mechanical properties, with a yield compressive strength of 1990 MPa and plastic strain of 9.12%. More over, a modified rule-of-mixture (ROM) was presented to describe the combined strengthening effect of grain refinement and TiC particles.

Microstructure and Mechanical Properties of Cermet Composite Coating on TC4 Surface

“…TC4 is a titanium alloy material commonly used in key technical fields such as machinery, ships, electronics, etc., which has the advantages of low density, light weight, high strength, strong fatigue resistance and stable performance [1][2][3][4], but has the disadvantages of low hardness and poor wear resistance, so the application range is limited [5,6]. Surface modification treatment technology is an important means to improve the properties of titanium alloys [7].…”

Microstructure and properties of in‐situ high entropy alloy/tungsten carbide composites by mechanical alloying.

“…The strength enhancement can be achieved by changing the processing route, 1,15 thermomechanical treatment, 16 severe plastic deformation, 17 or by composite formation 18–20 . Metal matrix composites (MMC) is one of the flexible strengthening techniques, where hard metallic phases or particles are dispersed in the soft matrix to improve the properties of the material 21–24 . Recently researchers have focused on developing such composites by adding hard reinforcement particles with HEA by arc melting 25 and plasma cladding 26 processes.…”