Co-Ni-BASED ALLOY DIAPHRAGM AND METHOD FOR PRODUCING THE SAME

摘要

To provide a metal diaphragm that can improve chemical stability of a semiconductor process used herein and is suitable for valves or the like and a method of producing the same.SOLUTION: A Co-Ni-based alloy diaphragm has a composition consisting of Co: 30 mass% or more and 40 mass% or less, Ni: 27 mass% or more and 36 mass% or less, Cr: 12 mass% or more and 26 mass% or less, Mo: 8 mass% or more and 13 mass% or less, Nb: 0.5 mass% or more and 3 mass% or less, Ti: 0.01 mass% or less, with the balance being unavoidable impurities, and has a tensile strength of 1470 MPa or more, an elongation of 1.5% or more and a hardness of 500±30 Hv.SELECTED DRAWING: Figure 1