Low temperature physical properties of Co-35Ni-20Mo-10Cr alloy MP35N

TL;DR

This study measures the low-temperature physical properties of the MP35N alloy, revealing how aging affects its electrical, thermal, and magnetic characteristics crucial for high-field magnet applications.

Contribution

It provides comprehensive cryogenic property data for MP35N alloy, including effects of aging, aiding in the design of high-field and superconducting magnets.

Findings

Electrical resistivity slightly increases with aging.

Specific heat matches theory at room temperature but is lower than literature values.

Magnetic properties change from paramagnetic to ferromagnetic with aging.

Abstract

Multiphase Co-35Ni-20Mo-10Cr alloy MP35N is a high strength alloy with excellent corrosion resistance. Its applications span chemical, medical, and food processing industries. Thanks to its high modulus and high strength, it found applications in reinforcement of ultra-high field pulsed magnets. Recently, it has also been considered for reinforcement in superconducting wires used in ultra-high field superconducting magnets. For these applications, accurate measurement of its physical properties at cryogenic temperatures is very important. In this paper, physical properties including electrical resistivity, specific heat, thermal conductivity, and magnetization of as-received and aged samples are measured from 2 to 300 K. The electrical resistivity of the aged sample is slightly higher than the as-received sample, both showing a weak linear temperature dependence in the entire range of 2 - 300 K. The measured specific heat Cp of 0.43 J/g-K at 295 K agrees with a theoretical prediction, but is significantly smaller than the values in the literature. The thermal conductivity between 2 and 300 K is in good agreement with the literature which is only available above 77 K. Magnetic property of MP35N changes significantly with aging. The as-received sample exhibits Curie paramagnetism with a Curie constant C = 0.175 K. While the aged sample contains small amounts of a ferromagnetic phase even at room temperature. The measured MP35N properties will be useful for the engineering design of pulsed magnets and superconducting magnets using MP35N as reinforcement.