The Influence of NiB 2 on the Microstructural Evolution, Mechanical, Tribological, and Electrochemical Corrosion Performance of Spark Plasma Sintered TiAl Composites
Year: 2026
Type: article
Abstract: ABSTRACT Gamma titanium aluminide (TiAl) alloys are promising lightweight materials for high‐temperature applications, although their limited wear and corrosion resistance restrict broader engineering use. This study investigates the influence of nickel diboride (NiB 2 ) reinforcement (0.5–3.0 wt%) on the microstructural evolution, densification, hardness, tribological behavior, and electrochemical corrosion performance of spark plasma sintered TiAl composites. Microstructural characterization revealed retention of the lamellar TiAl matrix with increasing reinforcement‐induced heterogeneity at higher NiB 2 contents. Relative density remained near‐full across all compositions, while hardness increased progressively from 389 to 461 HV due to dispersion strengthening and particle‐induced constraint effects. Wear rate decreased significantly with increasing hardness, confirming hardness‐controlled wear behavior and improved load‐bearing capacity. Corrosion behavior exhibited a non‐monotonic trend, with optimum resistance observed at 2.0 wt% NiB 2 owing to enhanced passive film stability and uniform particle dispersion. Higher reinforcement levels promoted particle clustering and localized electrochemical instability. The results establish a critical reinforcement threshold governing the balance between strengthening and microstructural degradation. This work demonstrates the potential of NiB 2 as a multifunctional reinforcement for tailoring the performance of TiAl‐based intermetallic composites.
Source: Engineering Reports
DOI: 10.1002/eng2.71035
Institution: University of Johannesburg
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,270
OpenAlex ID: W7204201547