Microstructure instability in TiC-316L stainless steel cermets

作者：Jin Chenxin; Plucknett Kevin P^*

来源：International Journal of Refractory Metals and Hard Materials, 2016, 58: 74-83.

DOI：10.1016/j.ijrmhm.2016.03.012

• Titanium carbide
• Stainless steels
• Cermets
• Core-rim structure
• Scanning electron microscopy
• Focused ion beam microscopy

Titanium carbide (TiC) based cermets are commonly used in wear and corrosion resistance applications. The microstructural evolution, and related compositional instability, of TiC-based cermets prepared with a 316-L stainless steel binder is described in the present work. Samples were fabricated using a simple vacuum melt infiltration procedure, with 5 to 30 vol.% binder. Infiltration temperatures ranged from 1475 degrees C to 1550 degrees C, held for up to 240 min, typically resulting in sintered samples with densities in excess of 99% of theoretical. It is demonstrated that irregularly shaped grains (concave/hollow) can arise after sintering, especially at 1475 degrees C, which is discussed in terms of the 'instability of the solid-liquid interface' theory. It is, demonstrated that a complex, multi-layer core-rim structure arose for the cermets, with accommodation of selected steel constituents into the rim of the TiC grains. In particular, it is shown that the Mo in the original 316-L stainless steel is essentially fully depleted from the metallic binder phase, forming a Mo-rich inner-rim layer on the TiC grain cores.

• 出版日期2016-8