Abstract This study investigates the influence of ceramic reinforcement on the microstructure, hardness, and intrinsic flexural behavior of cold-sprayed Ti-6Al-4V Grade 23 (Ti-G23) multilayer deposits. Multilayer specimens comprising an E295 steel substrate with a nickel interlayer were prepared for microstructural and hardness evaluation, while freestanding Ti-G23 and Ti-G23/SiC deposits were fabricated for intrinsic flexural testing independent of substrate constraint. The Ni interlayer exhibited a compact fine-grained structure with porosity below 0.53%, ensuring stable interfacial integrity. The monolithic Ti-G23 coating showed up to 12% lower porosity than the composite counterpart. Incorporation of SiC increased the average hardness of the composite deposit to 419 HV1, while localized microhardness values measured near regions containing higher SiC content reached up to 549 HV0.1. Flexural testing of freestanding deposits demonstrated slightly higher strength and stiffness for Ti-G23 (559 ± 20 MPa; 68 ± 5 GPa) compared with Ti-G23/SiC (523 ± 14 MPa; 63 ± 3 GPa). Fractographic analysis of the composite deposit revealed localized particle decohesion and microcrack initiation in regions containing increased reinforcement concentration. The results demonstrate that although ceramic reinforcement contributes to localized hardness enhancement, it simultaneously increases structural heterogeneity and restricts deformation within the composite deposit, limiting improvements in intrinsic flexural performance.
Viliš et al. (Mon,) studied this question.