Magnetic and microstructural aspects of WC-VC-Co-Ru alloys

Abstract

Magnetic and microstructural properties of WC-VC-Co-Ru alloys were investigated. To establish the effect of varying Ru and VC content, three alloy series were studied: 80WC-10VC-(10-x)Co-xRu (0 ≤ x ≤ 3) (wt%), (89.6-x)WC-10Co-0.4VC-xRu (0 ≤ x ≤ 2) (wt%) and (89.2-x)WC-10Co-0.8VC-xRu (0 ≤ x ≤ 2) (wt%). Coercivity and magnetic saturation, measured using a magnetic analyzer and a Koerzimeter, were reported. Scanning electron microscopy was used to determine the microstructural parameters: WC mean intercept length, binder mean free path and contiguity. Magnetic saturation decreased with Ru additions for all alloy series, but did not respond to changes in VC content. Coercivity decreased with Ru additions in all three alloy series. Higher VC contents corresponded to higher coercivities. The WC mean intercept length decreased with Ru additions for the (89.6-x)WC-10Co-0.4VC-xRu series and, to a much lesser extent, the (89.2-x)WC-10Co-0.8VC-xRu series. For the 80WC-10VC-(10-x)Co-xRu alloy series, no trend was observed in the WC mean intercept length as Ru was added. The WC mean intercept length was lower for alloy series with higher VC content. The binder mean free path decreased with Ru additions for the 80WC-10VC-(10-x)Co-xRu and (89.6-x)WC-10Co-0.4VC-xRu alloy series, but increased for the (89.2-x)WC-10Co-0.8VC-xRu alloy series. Lower binder mean free paths were associated with higher VC contents. Contiguity increased with Ru content for the 80WC-10VC-(10-x)Co-xRu alloy series, but decreased for the (89.6-x)WC-10Co-0.4VC-xRu and (89.2-x)WC-10Co-0.8VC-xRu alloys. The alloy series with higher VC content had lower contiguities.