| 摘要 |
PROBLEM TO BE SOLVED: To provide a laminate chip of WC-based super-hard alloy improved, over the conventional laminate chip of the same sort, in such problems as to exfoliate in its layers from one another and generate a large deformation because of generation of a residual stresses and/or inter-layer bonding phase movement resulting from the difference in the coefficient of thermal expansion between the layers. SOLUTION: In the laminate chip manufacturing method according to the conventional cold press method, the difference in the coefficient of thermal expansion between adjoining layers of super-hard alloy is made below 0.05×10<-6> /K and also a die is filled in layers with mixture of powder with the particle sizes adjusted so that no inter-layer bonding phase movement occurs, followed by a press working and a sintering process in a vacuum or in a non-oxidative atmosphere. The laminate chip of WC-based super-hard alloy fabricated in this manner is free from such a problem that residual stresses originating from the difference in the coefficient of thermal expansion are generated between the layers, so that there is no risk of exfoliation of layers from one another, and a sintering deformation can be precluded owing to less movement of the bonding phase likely to occur between layers in the sintering process.
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