Wear Behaviour of Recycled Hard Particle Reinforced NiCrBSi Hardfacings Deposited by Plasma Transferred Arc (PTA) Process

The main goal of present work was to study room temperature wear behaviour of advanced cermet particle reinforced hardfacings. For this purpose three different recycled powders: WC-Co, TiC-NiMo and Cr3C2-Ni were used as reinforcements for the commercially used NiCrBSi matrix alloy. Plasma transferred arc hardfacing process was used for deposition of the hardfacings. Manufactured hardfacings show only average wear resistance compared to WC/W2C reinforced NiCrBSi hardfacing with two times higher wear values. However, in combined impact/abrasive and erosive contacts, manufactured hard particle reinforced hardfacings have shown very promising results with high wear resistance. It was shown, that double structuring along with right material constituent and coating procedure selection may provide high wear resistance.

PTA hardfacing of Nb/Al coatings

Hardfacing is widely applied to components yet the majority of the welding techniques available restrain the variety of hard alloys that can be deposited. Plasma Transferred Arc hardfacing offsets this drawback by using powdered feedstock offering the ability to tailor the chemical composition of the coating and as a consequence its properties. The high strength and chemical inertia of aluminide alloys makes them very suitable to protect components. However, the strong interaction with the substrate during hardfacing requires analysis of each alloy system to optimize its properties and weldability. This work analyzed coatings processed with a cast and ground Nb40wt%Al alloy and the effect of Fe and C on the coatings features. It confirmed that sound Nb aluminide coatings can be processed by plasma Transferred arc hardfacing and will have a strong interaction with the substrate, which determines the final microstructure and properties of coatings. Final remarks point out that during Nb-Al coating tailoring the interaction with the substrate has to be considered at the early stages of design process.