High hardness and wear resistance of W-Cu composites achieved by elemental dissolution and interpenetrating nanostructure

Abstract

The effects of aluminum (Al) on the microstructure, hardness and wear resistance of tungsten-copper (W-Cu) composites were investigated. The W-Cu composites were fabricated via mechanical alloying and spark plasma sintering. It is found that the Al dissolved in the metastable W-Cu alloy can act as an ‘intermediary’ to hinder the diffusion and phase separation process of Cu out of W during sintering, constructing an interpenetrating nanostructure where Al redistributes in W and Cu. Correspondingly, the hardness of composites increase from 463.4 HV30 to 512.05 HV30 due to Al dissolution and formation of the nanostructure, and their contributions to hardness variation of the original W and Cu regions were distinguished by nanoindentation. In addition, the wear volume was also reduced to less than a third of that of original W-Cu composites without Al addition due to the abundant interfaces and mechanical strengthening, which restricts the removal of W and propagation of cracks during the wear process.

Effect of Grain Refinement on the Comprehensive Mechanical Performance of W–Cu Composites

“…It should be emphasized that W–Cu composites have to bear harsh wear processes and high-temperature loads in numerous service conditions [ 12 , 13 ]. Therefore, both wear resistance and high-temperature characteristic are essential indicators for high-end applications of W–Cu composites [ 14 ].…”

Thermal stability and high-temperature mechanical performance of nanostructured W–Cu–Cr–ZrC composite

“…The resultant W-Cu composite bulk had hierarchical structure with nanocrystalline microstructure of W phase. The tests indicated that the hardness and wear resistance of the nanostructured W-Cu based composites were greatly improved compared with those of the coarse-grained counterparts [32,33] . However, due to the increased energy associated with high volume fraction of grain boundaries, the W grains tend to grow rapidly at high temperatures [34][35][36][37][38] , leading to loss of some excellent properties derived from the nanostructure [39,40] .…”

Size-Dependent Alloying Ability of Immiscible W-Cu Bimetallic Nanoparticles: A Theoretical and Experimental Study

“…At the same time, the crystalline structure, melting point, and electronegativity of W and Cu are quite different. Bulk W-Cu materials are widely used in aerospace, military, electronic information, and other fields [11][12][13][14]. Conventional powder metallurgy methods do not solve the problem of the immiscibility of W and Cu, which results in the outcome that the overall properties of bulk W-Cu materials, such as poor ductility, are insufficient to meet industrial needs.…”