Machining of Boron Carbide Ceramics: A Review of Processes, Mechanisms, and Surface Integrity

ABSTRACT Boron carbide (B 4 C) ceramics are strategic materials for lightweight armor, wear‐resistant components, and neutron‐absorbing systems, yet their low fracture toughness makes precision machining highly sensitive to edge chipping, surface defects, and subsurface damage (SSD), limiting component reliability. This review consolidates machinability‐relevant mechanical and thermophysical properties of B 4 C and synthesizes major machining routes, including diamond grinding, ultrasonic machining, electrical discharge machining, laser machining, and hybrid strategies. Unlike conventional process‐by‐process summaries, the routes are categorized by dominant material‐removal mechanisms and linked to characteristic defect signatures and surface‐integrity metrics to enable cross‐process comparability. Mechanically dominated contact removal is primarily limited by crack initiation/propagation, manifested as edge chipping and SSD, whereas thermally or electrically dominated removal is constrained by heat‐affected damage, altered layers, and thermally induced microcracks. Hybrid approaches combining premodification with low‐load finishing are highlighted as practical routes to balance efficiency with integrity. A mechanism–defect–metric mapping and a unified evaluation index set are established, covering Ra/Sa, chipping severity, SSD depth/distribution, residual stress, and altered‐layer characteristics (HAZ, recast/modified layers). Finally, a staged process‐chain concept with quality‐gate checkpoints and damage‐budget‐based allowance allocation is proposed to guide process selection and validation for reliability‐critical B 4 C components.