Synchronized construction of metallurgical bonding and mechanical interlocking interface in immiscible W/CuCrZr functional gradient material by additive manufacturing

Abstract

In this study, a defect-free W/CuCrZr functional gradient material (FGM) with metallurgical bonding interface was prepared by additive manufacturing on a fine-grained W substrate. The transition of the W/CuCrZr FGM from a grain-size heterostructure to a dual-scale mechanically interlocked structure was achieved. The grain-size heterostructure was identified as a sandwich structure of columnar Cu grains, nano-W grains and micron-equiaxed W grains. The dual-scale mechanically interlocked interfaces are specified as sawtooth interfaces with interlocking W and Cu at the micron- and nano-scales. The synchronized construction of metallurgical bonding and dual-scale mechanical interlocking interfaces guarantee W/CuCrZr its excellent interfacial shear strength.