热双金属复合材料的研究现状与展望

Research Status and Prospects of Thermal Bimetallic Materials

摘要:

热双金属复合材料是一种利用先进复合技术，使两种及以上具有不同热膨胀系数的金属复合形成冶金结合的层状复合材料。该材料可发挥不同金属的自身性能优势，实现复合材料的性能互补，同时因其形状可随环境温度改变而调控的特性，被广泛应用于电子电器领域。随着电子科学技术飞速发展，对热双金属产品品质的要求也日益提高，总结并展望该材料在该领域的研究现状与前景意义重大。围绕电子电器领域的热双金属复合材料，综述了其制备原理、特性、组元构成、主要性能指标和制造技术。热双金属复合材料的工作原理是通过复合技术将两种及以上的金属层交替叠加并紧密结合，由于不同金属各异的热膨胀系数，当通过环境传导或自我发热方式受到热力刺激时，整个材料发生弹性弯曲变形而发生形状变化。热双金属的组元构成是影响其性能的重要因素，选择合适的金属组元可以使其具备更优异的性能。常见的组元包括钢-铝、铜-铝等，高膨胀层一般为锰铜合金，低膨胀层一般为铁镍合金。通过合理设计不同金属的层厚比例和堆叠顺序，可以调控材料的热膨胀性能和机械强度，主要性能指标包括材料的热膨胀系数、电导率和机械强度等，其中热膨胀系数决定了材料在不同温度下的形状变化程度，电导率影响了材料在电子电器中的导电性能，而机械强度则直接关系到材料的使用寿命和稳定性。制造技术是影响热双金属复合材料品质的关键因素之一，常见的制造技术包括爆炸复合、轧制复合和粉末冶金等。不同的制造技术会影响材料的结合程度、微观结构及性能稳定性，因此在选择制造技术时需要考虑到具体的应用场景和要求。最后，对热双金属复合材料未来的主要发展方向进行了展望。

Abstract:

Thermal bimetallic composite material is a material formed by using advanced composite technology to combine two or more metals with different thermal expansion. This composite material combines the physical properties of different metals and exhibits a characteristic of changing shape with temperature variation，hence it finds extensive applications in the field of electronics and electronic appliances. With the rapid development of science and technology，the demand for the quality of thermal bimetallic products is increasing，making research and development in this field of significant importance. This paper reviews the principles，characteristics，compositions，main performance indicators and manufacturing technologies of thermal bimetallic materials. Firstly，the principles and characteristics of thermal bimetallic materials are at the core of research. These materials are formed by alternating layers of two or more metals，tightly bonded through composite technology. Due to the different coefficients of thermal expansion of various metals，the material undergoes shape changes when subjected to thermal stimuli. Secondly，the composition of thermal bimetals is an important factor affecting their performance. Choosing the appropriate metal combination can result in superior performance of composite materials. Common compositions include steel-aluminum，copper-aluminum，etc. By designing the thickness ratio and stacking sequence of different metals reasonably，the thermal expansion performance and mechanical strength of the material can be controlled. The main performance indicators include the coefficient of thermal expansion，electrical conductivity，mechanical strength，etc. The coefficient of thermal expansion determines the extent of shape change of the material with temperature variation，electrical conductivity affects the electrical performance of the material in electronic devices，and mechanical strength directly relates to the material's lifespan and stability. Manufacturing technology is one of the key factors affecting the quality of thermal bimetallic composite materials. Common manufacturing techniques include explosive bonding，roll bonding，powder metallurgy，etc. Different manufacturing techniques affect the degree of material bonding，microstructure，and performance stability，thus specific application scenarios and requirements need to be considered when choosing manufacturing techniques. Finally，this paper discusses the main future development directions of thermal bimetals.