| 摘要 |
PROBLEM TO BE SOLVED: To produce an alloy excellent in corrosion resistance under high temp. and high humidity and capable of use in this state and also capable of plastic deformation by providing a composition consisting of W and the balance and specifying the ratio between Co and Fe in the combination of Ni, Co, and Fe as the balance. SOLUTION: This W-base sintered alloy is an alloy having a composition consisting of, by weight, 80-97% W and the balance Ni, Co, and Fe, and further, the combination of Ni, Co, and Fe has a composition consisting of 2-60% Co, >0-<5% Fe, and the balance Ni. When the amount of W is less than 80%, deformation is brought about during sintering because the proportion of the binding phase consisting of Ni, Co, and Fe becomes excess, and on the other hand, when it exceeds 97%, the toughness of the alloy is reduced and plastic deformation such as caulking and machining are made difficult. As to the amount of Co in the combination of Ni, Co, and Fe, the corrosion resistance of the alloy is decreased when it is less than 2% and toughness is deteriorated when it exceeds 60%. Similarly, toughness is lowered when the amount of Fe is 0%, and on the other hand, when it exceeds 5%, there are cases where a partialα-Fe phase is precipitated in the binding phase and corrosion is liable to occur under high temp. and high humidity.
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