Class 9 includes metal matrix composites (MMCs), which embed ceramic fibers or particles in a metal matrix. These materials are valued for combining the strength and wear resistance of ceramics with the ductility and toughness of metals. Common in military and high-performance sporting applications, MMCs offer tailored mechanical and thermal properties for demanding environments.
Hard ceramic particles may dislodge during grinding and polishing, leaving voids or surface defects.
Disparity in hardness between matrix and reinforcement causes relief or surface unevenness.
Composites may lose edge definition due to differential wear across phases.
Microvoids or interfacial porosity must be preserved and not smeared during final polishing.
Use diamond wafering saws with coolant to avoid cracking ceramic reinforcements or matrix deformation.
Vacuum impregnation helps support particles and fill interfacial voids for better edge retention.
Use alumina or SiC papers. Apply minimal pressure and frequent rinsing to avoid particle pull-out.
Diamond suspensions with low-nap cloths minimize relief. Final polish with colloidal silica can enhance phase contrast.
Hard particles remain embedded with minimal pull-out
Polished surface shows minimal relief across phases
Interfaces and voids are clean and clearly defined
Edge features remain intact with no rounding