Microstructure and mechanical properties of Cu-ZTA cermet prepared by vacuum hot pressing sintering

Abstract

In this paper, seven copper-zirconia toughened alumina (Cu-ZTA) cermets were prepared by vacuum hot pressing sintering (VHP). The effects of different binder content and different particle size of ZTA particles on the mechanical properties of Cu-ZTA cermets were investigated. The microstructure of the composites was studied by x-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The hardness of the material was measured by micro Vickers hardness tester. The results show that the solid solution strengthening occurs in the hot pressing sintering process, the formation of copper-based solid solution increases the hardness of the matrix, the highest is192.04 HV 0.1 . The ZTA particles are uniformly distributed in the matrix, and the surface of the ZTA particles is surrounded by a continuous coppermatrix and second phase. Two interfaces are formed between ZTA particles and Cu matrix. One is the ZTA/Cu interface formed by the substitution of Cu atoms for Ni atoms, it is a mechanical meshing interface which extends the service life of cermet under mechanical stress and thermal stress. The other interface is the reaction bonding interface of Cu 3 Ti 3 O and TiO x . The friction and wear test results show that the use of low-diameter ZTA particles and increasing the content of Cu binder will improve the friction and wear properties of Cu-ZTAcermet. Under the action of stress, the fracture occurs at the interface of Cu/ZTA, and the wear, fracture and extraction of ZTA ceramics cause the failure of Cu-ZTA cermet.

Microstructure, interfacial characteristics, and wear performances of Cu–Fe–SiC cermet composites

“…The metal-based bond cermet has good heat dissipation and produces less tensile residual stress. 10 The matrix of metal-based grinding wheel is usually made of copper and iron. Copper has good toughness and high thermal conductivity, whereas iron has good fatigue resistance and high wear resistance.…”

“…Powder metallurgy is widely used in the preparation of cermet composites due to its high density and excellent mechanical properties. 10,21,22 However, the mechanical properties and grinding properties of cermets prepared by powder metallurgy are still less studied.…”

“…Due to poor heat dissipation of grinding wheel, the grinding heat generated in the grinding process could not be dissipated, resulting in serious thermal deformation on the rail sample and large tensile residual stress. The metal‐based bond cermet has good heat dissipation and produces less tensile residual stress 10 . The matrix of metal‐based grinding wheel is usually made of copper and iron.…”

“…tested the grinding performance of the prepared Cu/SiC composites by dry sliding wear test and the results showed that, compared with the traditional sintering process, the compressive stress applied in the sintering process increased the density, hardness, and wear of sintered materials. Powder metallurgy is widely used in the preparation of cermet composites due to its high density and excellent mechanical properties 10,21,22 . However, the mechanical properties and grinding properties of cermets prepared by powder metallurgy are still less studied.…”

Features of microstructure and thermoelectric properties of the cermet composites based on grained Bi2Te3 matrix with locally-gradient Ni@NiTe2 inclusions

“…Usually, the cermet composites serve as structural materials, which possess high temperature resistance and hardness, ability to undergo plastic deformation, etc. [10][11][12]. In contrast to the structural cermet composites, the thermoelectric cermet composites with the metallic magnetic inclusions are functional materials, since embedding the inclusions into the matrix should primarily improve the specific thermoelectric (functional) properties of the composite.…”