【摘要】 本文将不同Cu含量的（CoCrFeNi）_100-xCu_x高熵合金（x=10、20、30、40、50）作为中间层，利用放电等离子烧结对WC-10%Co（质量分数）硬质合金和42CrMo钢进行固相扩散焊，探究了高熵合金中间层成分对焊接接头界面组织特征、元素扩散行为及最终力学性能的影响。结果显示，各成分下硬质合金与高熵合金界面均无明显微孔和微裂纹，但高熵合金中间层与42CrMo钢界面普遍存在少量微孔，且低Cu含量（CoCrFeNi）90Cu10与42CrMo钢界面存在大量微孔和微裂纹。扩散焊后中间层出现了富Cu相和富Cr相，其中富Cu相在Cu的原子数分数减小到10%后基本消失，而富Cr相主要分布在界面附近，且Cu的原子数分数增加到50%时主要分布在贫Cu相边缘及内部。中间层元素（Co、Cr、Fe、Ni）在硬质合金中的扩散距离比硬质合金中W元素在中间层的扩散距离要远。相较而言，高熵合金中间层各元素与42CrMo钢之间的元素扩散距离基本相同。另外，在使用（CoCrFeNi）_100-xCu_x高熵合金作为中间层时，焊接接头的抗拉强度随着中间层Cu含量的增加而明显增大，当Cu的原子数分数为40%时抗拉强度达到最大值507 MPa，随后继续增加Cu含量强度基本不变。更多还原

【Abstract】 High-entropy alloy（CoCrFeNi）_100-xCu_x with different Cu content（x=10, 20, 30, 40, 50） was introduced as interlayer during the SPS diffusion bonding of WC-10%Co（mass.%） cemented carbide and 42CrMo steel. The microstructural characteristics and element diffusion of bonded interface was investigated in detail, as well as the final mechanical properties of bonded joint. It reveals that the interface of cemented carbide and interlayer was fine without the existence of microvoid and microcrack. As for the interface of interlayer and 42CrMo steel, it is generally showed slight microvoid, while abundant microvoid and microcrack were observed in the case of（CoCrFeNi）₉₀Cu₁₀. In addition, both of Cuenriched phase and Cr-enriched phase were found inside interlayer after bonding consisted, while the Cu-enriched phase disappeared as the Cu content of interlayer reduced to 10at.%. As a comparison, the Cr-enriched phase was mainly distributed in the vicinity of bonded interface, whilst concentrated inside and/or neighbored to the Cu-depleted phase. The diffusion distances of Co, Cr, Fe and Ni elements from interlayer to cemented carbide were much larger than that of W element from cemented into interlayer. However, the diffusion distance of elements between interlayer and 42CrMo steel presented nearly the same level. Moreover, as the high-entropy alloy（CoCrFeNi）_100-xCu_x was introduced as interlayer, the ultimate tensile strength of bonded joint increased gradually with improving the Cu content of interlayer, and the maximum value of 507 MPa was obtained as the Cu content achieved 40at.%. Subsequently, the corresponding value kept stable with the further increase of Cu content of interlayer.更多还原