Titanium-Based Laminated and Hybrid Architectures Fabricated by Powder Metallurgy: Evolution from Constituent Design Toward Interface and Deformation Control

Titanium-based laminated and hybrid architectures have emerged as an attractive approach for overcoming limitations associated with conventional homogeneous structural materials. By combining titanium alloys and metal matrix composites within heterogeneous architectures, it becomes possible to achieve combinations of strength, hardness, ductility, toughness, and energy absorption that are difficult to attain through conventional alloy design alone. The development considered here is centered on powder-metallurgy-based processing, particularly blended elemental powder metallurgy (BEPM), combined with diffusion bonding, friction welding, and hot isostatic pressing (HIP). This review summarizes the evolution of these architectures from early layered armor concepts toward increasingly sophisticated heterogeneous systems in which constituent selection, layer arrangement, interfacial transitions, and reinforcement topology increasingly become design parameters for controlling deformation and failure. Particular emphasis is placed on the development of TiC- and TiB-reinforced titanium composites, processing strategies for multilayered structures, the role of interfaces and transition layers, densification challenges, and the role of HIP as an enabling technology. The relationships between architecture, microstructure, and mechanical performance under quasi-static, dynamic, and ballistic loading conditions are discussed. Finally, future opportunities associated with architected heterogeneous titanium systems and topology-controlled deformation are considered.