resumo
The demand for improved components with a wide range of properties is a reality in today's hardmetal market. Furthermore, supply shortages of raw materials such as W and especially Co resulted in rapid price fluctuations. Combined with stricter environmental legislation and health protection, these facts prompt the demand for alternative or modified binders. Therefore, in this work, WC-NiCrMo composites were developed as a potential alternative to conventional WC-Co hardmetals. To evaluate this new hardmetal composite, prototypes of sub -micrometric WC with approximately 15 vol% of NiCrMo binder were produced by conventional powder met-allurgy route. Thermodynamic assessment, wettability testing and constant heating rate dilatometry were performed to design an adequate sintering route. A detailed characterization of the mechanical properties (Young's modulus, Vickers hardness and fracture toughness), together with corrosion resistance assessment (OCP, polarization curves, EIS) and abrasive wear (ball-cratering) resistance evaluation were undertaken. Good wettability of molten NiCrMo binder on WC surface was observed, and highly dense compacts could be suc-cessfully attained by gas pressure sintering. The new WC-NiCrMo composite has lower hardness but higher corrosion resistance and better wear resistance than the conventional WC-Co hardmetals.
palavras-chave
ELECTROCHEMICAL-BEHAVIOR; CORROSION BEHAVIOR; CEMENTED CARBIDES; CO HARDMETALS
categoria
Materials Science; Metallurgy & Metallurgical Engineering
autores
Pereira, P; Rocha, AMF; Bastos, AC; Oliveira, FJ; Vilhena, LM; Ramalho, A; Sacramento, J; Malheiros, LF; Senos, AMR
nossos autores
Grupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
Projectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
P. Pereira acknowledges FCT for financial support (SFRH/BD/138040/2018) . This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) . Furthermore, we acknowledge HARDTECH-POCI-01-0247-FEDER-045283, financed by FEDER under the PT2020 Partnership Agreement.