Abstract
In this paper, the influences of Al element originating from AlN additives on the mechanical properties and oxidation behavior of WC-Co-Ni-Fe hardmetals were studied systematically. During the sintering process, Al element diffused into the WC hard grains and led to the formation of (Ni,Co,Fe)3Al particles in the metal binder phase of hardmetals. A small amount of Al element enhanced the hardness of WC-Co-Ni-Fe hardmetal via the solution strengthening and dispersion strengthening. However, the addition of Al element decreased the fracture toughness of hardmetals. The hardness and fracture toughness of multicomponent hardmetals with the addition of 0.5 wt% AlN were 90.4HRA and 10.6 MPa m1/2, respectively. Additionally, the introduction of Al also significantly improved the oxidation resistance of hardmetals due to the existence of Al in WO3 and (Ni,Co,Fe)WO4. With the addition of 2.0 wt% AlN, the weight gain of WC-Co-Ni-Fe-Al multicomponent hardmetal after 5 h of oxidation at 700 °C was 66.82 % of that of the Al-free hardmetal.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call