Abstract:The magnetic and thermal expansion properties of the magnetic materials have a great influence on the stability of the torque device in the quartz flexible accelerometer. The effects of different heat treatment temperature and test temperature on the magnetic properties, magnetic temperature stability and thermal expansion coefficient of 4J32A alloy were studied by using the soft magnetic DC magnetic tester and laser expansion tester. The results show that the heat treatment of soft magnetic alloy is suitable for 4J32A alloy, and the permeability, coercive force and remanence of 4J32A alloy are greatly improved after heat treatment. The heat treatment temperature has little effect on the temperature stability of the soft magnetic properties of the alloy. The average temperature coefficient of μ m of 4J32A alloy is in the order of 10-4, and that of Bs, Br and Hc is in the order of 10-3.