Effect of Compaction Pressure on the Physical, Mechanical, and Tribological Behavior of Compacted Crab Shell Particles Prepared Using Uniaxial Compaction Route

As an alternative to conventional materials like steel and ceramic, the current research focuses on utilizing naturally available waste crabs shells in the mechanical and tribology application due to their self-lubrication properties, adequate strength, abundant availability, environment-friendly and renewable. In the present study, the prepared crab shell particles (CSP) were compacted at various compaction pressures (20, 30, 40, 50 and 60 MPa) using a uniaxial compaction machine at room temperature. The influence of compaction pressure on the surface morphology, phase-structure, functional group, hardness, compression strength, and wear properties of compacted crab shell particles (CCSP) is determined. The degradation of chitin polymer for CCSP at 50 MPa and 60 MPa was confirmed using XRD and FT-Raman analysis. In addition to the chitin polymer, the presence of functional groups like C-H, O-H and N-H in CSP improved the interlocking mechanism between the particles during the compaction. This played a crucial role in reducing the porosity and cracks in the microstructure of CCSP, which eventually increased the hardness to 73.1 HV0.1 and compressive strength to 109.70 MPa for CCSP at 40 MPa. The decrease in the wear rate and CoF were evidenced for CCSP due to the self-lubrication properties. In addition, the occurrence of surface fatigue wear for CCSP against hardened EN-31 steel is elaborated in detail using the SEM analysis.

Automated summary

This study focuses on the potential utilization of waste crab shells in mechanical and tribology applications. The results show that compacted crab shell particles exhibit improved hardness and compressive strength, as well as self-lubrication properties, making them a promising alternative material.