Low temperature pressureless immediate sintering of novel nanostructured WC/Co/NiCrSiB-alloy cemented carbide

TL;DR

This paper introduces a novel nanostructured WC/Co/NiCrSiB cemented carbide that can be sintered rapidly at low temperatures without pressure, achieving high density and hardness.

Contribution

It presents a new nanostructured cemented carbide with a unique sintering process involving infiltration at low temperature and short duration, resulting in high density and hardness.

Findings

Achieved 98.5-100% density within minutes

Microhardness above 1500-1800 HV1

Rapid wetting with zero contact angle in 40 seconds

Abstract

A novel nanostructured cemented carbide formed from WC-5%Co-20%BNi2 brazing alloy is described. During sintering, the BNi2 alloy is infiltrated into a green compact of WC-5%Co at 1050-1100 {\deg}C for 2-60 minutes. Perfect wetting behavior and a zero contact angle are achieved after only 40 s. Relative densities of 98.5% and 100% and microhardness values of above 1500HV1 and 1800HV1 are obtained after 2 and 30 minutes, respectively. A change in mean particle size of about 600 nm in the precursor to a bimodal distribution of 350-400 nm and 10-20 nm is explained by a solution/reprecipitation mechanism.