Efficient manufacture of TiNi/Ti2Ni intermetallic composites with a unique brick-and-mortar structure in a single hot rolling process

Abstract

Seashells have a typical brick-and-mortar structure (BMS) composed of tiny mineral particles and organic matter. Such BMS has inspired the development of advanced composite materials with high strength and toughness, yet it is challenging to implement in metallic systems. This study employs the foil-to-foil method combined with hot-press sintering to fabricate layered TiNi/Ti₂Ni intermetallic composite material(ICM). The layered ICM is further subjected to hot rolling with varying deformation, successfully producing ICM with a unique brick-and-mortar structure. The BMS-ICM has an ultra-high content of Ti₂Ni reinforcement phase. The olive-shaped brittle phase of Ti₂Ni is evenly distributed within the TiNi mortar as bricks, with a volume fraction of the Ti₂Ni phase as high as 79 %. The compressive strength of 60 % BMS-ICM perpendicular to the loading direction of the laminate reaches 1963.50 MPa, accompanied by a fracture strain of 24.5 %. Additionally, the unique Ti₂Ni brick and TiNi mortar structure provides multiple toughening mechanisms for BMS-ICM. Compared to conventional materials, BMS-ICM demonstrates significant advantages in crack propagation resistance, thus holding great potential for applications in the military and aerospace fields.