多坯料挤压法制备近全致密W-Cu梯度热沉材料

摘要

A three-layer W/Cu functionally graded material (FGM) for heat sink with nearly full density was fabricated by multi-billet extrusion (MBE) method. The compositions of the three layers including sealing layer, transitional layer and radiating layer of W/Cu heat sink material were W/Cu20, W/Cu33 and W/Cu50, respectively, and the thickness of each layer was 0.5mm. The fabrication process, densification and microstructure of W-Cu FGMs were also studied. The results show that the extrusion force of fabricating W-Cu graded billet by MBE method is about 0.6 KN; after natural dryness for 10 h, the specimens have no distortion or rupture; under the condition of degreasing temperature 350℃ for 1 h, sintering temperature 1 060℃ for 3 h with pressure 85 MPa, the W-Cu FGMs for heat sink with nearly full density and equal thickness can be obtained and the relative density of each graded layer is 98.3%, 99.3% and 99.9%, respectively. The interfaces between layers are visible. It is metallugical bonding between the layers. Cu phase shows network and W distributes in network structure.%采用多坯料挤压法制备封接层、中间过渡层和散热层分别为W/Cu20、W/Cu33和W/Cu50的近全致密均厚结构W-Cu梯度热沉材料，梯度层厚度均为0.5 mm，并对工艺过程、致密性能和显微结构进行研究。结果表明：采用多坯料挤压法制备W-Cu梯度预制块时压力仅为0.6 KN，经10 h自然干燥后，预制块外观平整，无开裂；在350℃脱脂1 h、然后在烧结温度1060℃、压力85 MPa条件下，保温3 h可以获得各层相对密度分别为98.3%、99.3%、99.9%的近全致密的W-Cu均厚结构梯度热沉材料；各层间界面位置清晰，层间为冶金结合界面；各层中Cu相呈网状分布，W颗粒镶嵌于网络结构中。