金属橡胶无序式网格互穿结构的热力学性能研究

Study on Thermomechanical Properties of Metal-rubber Disordered Lattice Interpenetrating Structures

金属橡胶是一种弹性多孔纯金属材料,其内部的网格互穿结构复杂而无序,难以通过一般方法准确描述,这限制了其在高温环境下的可控应用。为此,通过虚拟制备技术构建了综合考虑金属橡胶材料属性、线匝几何尺寸及工艺参数等因素的金属橡胶有限元模型。在此基础上,推导出金属橡胶内部金属丝微元热传导的动态理论公式并进行相关的有限元分析。结果表明:当仅有热载荷时,金属橡胶主要由连续金属丝实现传热并通过界面接触进行换热,温度场沿成形方向呈梯度分布。此外,由于材料的膨胀其宏观尺寸会增大,但在外部约束与孔隙收容机制的作用下其热膨胀系数小于实心材料的热膨胀系数。而当同时存在热-力载荷时,金属橡胶展现出了良好的结构稳定性与耐热性。通过材料高温准静态压缩试验对材料的热力学性能进行了测试,验证所建立的有限元模型能够有效地反映与预测金属橡胶材料复杂的热力学性能,为材料在高温环境下的应用提供了一定的理论指导。

Metal rubber is an elastic porous pure metal material with a complex and disordered internal mesh interpenetration structure,which is difficult to describe accurately by general methods,which limits its controllable applications in high temperature environments.To this end,a finite element model of metal rubber is constructed by virtual preparation technology that integrates the material properties,wire dimensions and process parameters of metal rubber.On this basis,the dynamic theoretical formulas for the heat conduction of metal wire microelements inside metal rubber is derived and related finite element analysis is carried out.The results show that when only thermal load is present,the metal rubber is mainly realized by continuous metal wires for heat transfer and heat exchange through interfacial contact,and the temperature field is distributed in a gradient along the forming direction.In addition,due to the expansion of the material,its macroscopic size increases,but its thermal expansion coefficient is smaller than that of the solid material under the action of the external constraint and pore containment mechanism.When thermal-force loading is also present,the metal rubber shows good structural stability and heat resistance.The thermomechanical properties of the material were tested by high-temperature quasi-static compression test,it is verified that the established finite element model can effectively reflect and predict the complex thermomechanical properties of the metal-rubber material,which provides some theoretical guidance for the application of the material in high-temperature environment.