负膨胀材料在复合材料制备和钎焊中的研究进展

Negative thermal expansion(NTE) materials show unique advantages in regulating the coefficient of thermal expansion of materials due to their heat-shrinking and cold-expanding nature, which show great potential in the field of composite materials and brazing. The NTE materials are used to regulate the high coefficient of thermal expansion of metal composite filler，which have been widely used in aerospace，biomedicine，sensors，and electronic information. In the field of composite materials，the combination of NTE and positive thermal expansion material can effectively regulate the coefficient of thermal expansion of composite materials，controlling it at a very low or near-zero level. Some researchers have utilized the property of NTE materials to reduce the coefficient of thermal expansion of metal matrix composites，and reduce the failure problem caused by temperature difference. In the field of brazing，due to the large difference in the coefficient of thermal expansion of dissimilar materials，the large residual stresses will be produced in the brazed joints，which seriously affects the performance of the components. The coefficient of thermal expansion of metal composite filler by introducing negative expansion materials，reducing the difference of the coefficient of thermal expansion between the base material and brazing seam. Therefore，the NTE materials effectively reduces the residual stresses of the brazed joints，and achieves the purpose of improving the mechanical properties of the brazed joints.