Influence of Boron Addition on the Microstructure, Mechanical, and Corrosion Behavior of NiCrBSi Alloys Prepared by Spark Plasma Sintering

This study investigates the effect of boron addition on the microstructural, mechanical, and corrosion properties of NiCrBSi alloy fabricated by the spark plasma sintering (SPS) method. Boron was added at levels of 1.5, 3, and 4.5 wt.%, and sintering was conducted at 950 °C for 5 min. Microstructural characterization was carried out using SEM–EDS and XRD analyses, hardness was measured by the Vickers method, and densities were determined according to Archimedes’ principle. The transverse rupture strength (TRS) was obtained by three-point bending tests, while wear performance was evaluated in a reciprocating wear mode. Corrosion behavior was examined through potentiodynamic polarization in a 0.1 M HCl solution. Increasing boron content promoted the formation of nickel and chromium boride phases, enhancing hardness (up to 675 HV0.5) and wear resistance but reducing TRS values due to brittle intermetallic formation. Furthermore, corrosion protection efficiency improved, reaching about 65.9% at 4.5 wt.% B addition.