关键词: 因瓦合金, 冷轧压下率, 微观组织, 热膨胀系数, 磁性能, 织构

Abstract: Effect of different cold rolling reduction of 20% to 90% on the microstructure, mechanical properties, thermal expansion properties, saturation magnetization, and texture evolution of invar alloy were studied by means of backscattered electron diffraction (EBSD), XRD, tensile testing, hardness testing, thermal expansion testing, and magnetic property testing. The results show that as the cold rolling reduction increases, the equiaxed grains after solution treatment deform through dislocation sliding, and the alloy is gradually flattened and elongated to form a specific orientation, resulting in an increase in both the strength and hardness of the alloy, while the plasticity decreases rapidly. At 90% reduction, the tensile strength of the alloy is 777 MPa, while the elongation is only 5%. When the cold rolling reduction does not exceed 80%, the average linear expansion coefficient in the temperature range of 20 ℃ to 100 ℃ and saturation magnetization of the alloy show a trend of first decreasing and then increasing, and the alloy achieves a minimum value at 60% reduction. In the alloy, the strength of {110}<112>Brass texture, {112}<111}Copper texture, and {136}<634>S texture raises with the increasing of deformation degree. When the cold rolling reduction reaches 80%, strong textures are formed in the alloy.

Key words: invar alloy, cold rolling reduction, microstructure, coefficient of thermal expansion, magnetic properties, texture