The Structure and Properties of Composite Compacts Made of High-Alloy Powder Containing Boron Nitride Additives

The structure and properties of composite based on high-alloy iron powder (PH13M2-BN) are studied for different concentrations of boron nitride. It is shown that adding boron nitride in amount of more than 2 wt % into the original charge leads to forming protruding pores along the grain boundaries and finely dispersed BN layers providing a high level of material wearing. The physics and mechanical properties of compacts are studied as a function of boron nitride concentration. It is established that adding a small amount of BN (up to 2 wt %) to compacts improves plasticity, cross-breaking strength, and impact strength owing to reducing friction forces between metal powder particles at the pressing stage and results in better development of the grain-boundary diffusion processes at the sintering phase. Formulating structural and phase composition of PH13M2-BN powder compacts with controlled content of boron nitride allows obtaining desired physical and mechanical properties over a wide range. The results of studying the physical and mechanical properties of this material enable making the seals in flow paths of steam turbines having properties suitable for the operational conditions.