Effect of Substrates Characteristics on Tribological Behaviors of AlTiN-Based Coated WC-Co Cemented Carbides

摘要

The wear resistance of coated tools is a key technical parameter, which is indirectly affected by the substrate phase characteristics. WC-Co cemented carbides with varied WC grain sizes (0.4, 0.7, 1.2 mu m) and Co contents (3, 6, 10, 12 wt.%) were used as the substrates. Single-layer Al0.52Ti0.48N and multilayer Ti0.89Si0.11N/TiAlSiN/Al0.52Ti0.48N films were deposited on the substrates by DC magnetron sputtering. Reciprocating friction tests were carried out in the air medium and the 3.5 wt.% NaCl aqueous solution, respectively. In the air medium, the films on the fine and the submicron WC-Co substrates with the weaker carrying capacity became worn through earlier than those on the ultrafine substrates. In the NaCl solution medium, for the ultrafine-grained WC-10Co substrates with different Co contents, the friction coefficients (F-S) of the film had a linear negative correlation with the hardness (H-S) of the substrates. With the decrease in the WC grain sizes or the Co contents, the wear rates of the coated alloys decreased gradually (by 19.7% and 34.5%, respectively). The regular patterns obtained can provide a reference for the selection and design of the phase composition of the cemented carbide substrates.

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