Effect of Heating Mode and Copper Content on the Densification of W-Cu Alloys

Abstract

This study investigates the effect of heating mode on the sintering of tungsten-copper alloys containing up to 30 wt.% Cu. The sinterability of the W-Cu system consolidated in a 2.45 GHz multimode microwave furnace has been critically compared with that processed in a radiatively heated (conventional) furnace. The as-pressed W-Cu alloys can be readily sintered in microwave furnace with substantial (sixfold) reduction in the processing time. As compared to conventional sintering, microwave processing results in greater densification, more homogenous distribution of the binder phase, and smaller tungsten grain size. The densification in compacts increases with increasing Cu content. For all compositions, the electrical conductivity and hardness of microwave sintered W-Cu alloys are higher than those of their conventionally sintered counterparts. This study investigates the effect of heating mode on the sintering of tungsten-copper alloys containing up to 30 wt.% Cu. The W-Cu alloys were sintered in a 2.45 GHz microwave furnace with substantial (sixfold) reduction in the processing time. As compared to conventional sintering, microwave processing results in greater densification, more homogenous distribution of the binder phase, and smaller tungsten grain size. This results in higher electrical conductivity and hardness of the microwave sintered W-Cu alloys.

Effect of Nano Copper on the Densification of Spark Plasma Sintered W–Cu Composites

“…Processing techniques such as high-pressure sintering, microwave sintering, dynamic consolidation, and low-temperature infiltration in supergravity fields have resulted in higher density, improved mechanical properties, and a significant reduction in processing time [2,3,15,[21][22][23]. As the copper content increased in the W-Cu composite, the electrical conductivity increased, as expected [21]. However, despite the higher copper content, the electrical conductivity reduced as a result of higher sintering temperature [20].…”

“…High-energy mechanical milling of tungsten and copper powders to produce fine or ultra-fine particles resulted in high relative density and lower sintering temperatures [3,20]. Processing techniques such as high-pressure sintering, microwave sintering, dynamic consolidation, and low-temperature infiltration in supergravity fields have resulted in higher density, improved mechanical properties, and a significant reduction in processing time [2,3,15,[21][22][23]. As the copper content increased in the W-Cu composite, the electrical conductivity increased, as expected [21].…”

The Effects of Sintering Temperature on the Densification of Mechanically Alloyed W-Brass Composites

“…This is because the particle rearrangement is minimal and there is no liquid formation that can introduce capillary action which increases densification. Mondal et al [24] noted that, in solid state sintering of W-Cu system, the W-W interfacial energy is relatively low (2.79 J/m 2 ). This means that the skeletal W-W bond formed through solid state sintering are energetically favoured and stable.…”

Conventional and microwave assisted sintering of copper-silicon carbide metal matrix composites: a comparison

“…It was reported that all the microwave-sintered composites exhibited improved hardness and electrical conductivity as compared to conventionally sintered counterparts. Eighty-five percent reduction in processing time was achieved by microwave heating [16]. Microwave assisted sintering was projected as a promising processing technique for the sintering of metal and alloy powders.…”