Medium entropy alloy for diesel engine cylinder head and heat treatment method thereof

Abstract

This invention discloses a medium-entropy alloy for diesel engine cylinder heads and its heat treatment method. The atomic percentage chemical composition of the medium-entropy alloy is: (Ni5Al2). 55 Fe 45 The alloy comprises 55% Ni5Al2 and 45% Fe; the medium-entropy alloy has a dual-phase structure of FCC phase and B2-NiAl phase, with FCC phase volume fraction ≥77% and B2-NiAl phase volume fraction ≤23%, and ordered L12-type superlattice phase precipitated in the FCC phase; this invention achieves this by precisely controlling the heat treatment temperature, heating rate and holding time, making (Ni5Al2) 55 Fe 45 In medium-entropy alloys, the FCC phase undergoes an ordered transformation and precipitates an L12-type superlattice phase, which improves tensile strength and thermal conductivity while maintaining good elongation, thus solving the problem of traditional materials having difficulty in balancing strength, toughness, and thermal conductivity.

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