Premium
Processing and Properties of Ti(C,N)–WC‐Based Materials
Author(s) -
Bellosi Alida,
Medri Valentina,
Monteverde Frédéric
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb01069.x
Subject(s) - materials science , flexural strength , microstructure , sintering , fracture toughness , intergranular fracture , argon , tungsten , grain growth , phase (matter) , composite material , transgranular fracture , metallurgy , hot pressing , grain boundary , physics , chemistry , organic chemistry , atomic physics
Two Ti(C,N)–WC powder mixtures, one containing 0.88 wt% Co and the other 6.2 wt% Ni + 2.9 wt% Co, were fabricated by different routes: pressureless and gas‐pressure sintering in argon and nitrogen, and hot‐pressing under vacuum. The microstructures of all the sintered samples consisted of grains with a core/rim structure, the core being Ti(C,N) and the rim (Ti,W)(C,N). An inner rim also was present at the core/rim interface. The more highly doped materials also had an intergranular Ni‐Co‐Ti‐W binder phase. The compositions and cell parameters of the hard phases, as well as of the binder, were analyzed. The nitrogen partial pressure in the sintering furnace was the main factor that influenced grain growth and phase composition. In fact, sintering under argon enhanced grain growth and was accompanied by a lower tungsten content in the rim. The influence of the microstructure on some mechanical properties (hardness, flexural strength, toughness, and Young's modulus) also was investigated. Flexural‐strength values up to 1550 MPa at room temperature and 1200 MPa at 800°C, and fracture‐toughness values up to 8 MPa·m 1/2 were measured, depending on the starting composition and processing conditions.