Research on the Structure and Mechanical Properties of Mesh Powder Composite Copper Microporous Materials

With the proliferation of flexible electronics, the advancement of mechanically compliant thermal management systems, notably flexible heat pipes, is imperative to address evolving demands for adaptive thermal regulation in deformable device architectures. The wicks of heat pipes commonly utilize porous copper. In this study, three types of porous copper materials were fabricated: sintered pure copper powder, sintered copper powder with a copper mesh (as a reinforcing network), and sintered copper powder with NaCl (as a pore-forming agent). Their pore structure characteristics, tensile, and compressive mechanical properties were systematically investigated. Results demonstrated that incorporating NaCl into copper powder significantly increased porosity and enlarged pore size, thereby enhancing permeability. For instance, compared to sintered pure copper powder, the addition of NaCl increased the average pore diameter from 0.31 μm to 2.44 μm and improved permeability from 1.908 × 10⁻¹⁴ m² to 2.832 × 10⁻¹² m², effectively reducing fluid flow resistance. The introduction of copper mesh notably improved mechanical performance: under a sintering temperature of 900 °C, tensile strength increased from 121.6 MPa to 132.2 MPa, and compressive strength rose from 443.5 MPa to 458.4 MPa. However, NaCl-added porous copper exhibited a drastic decline in tensile strength. Consequently, NaCl-modified porous copper is unsuitable for flexible wick applications, whereas copper mesh-reinforced porous copper shows potential as a flexible wick, though further investigation is required to enhance its permeability mechanisms.