Multiple mature sintering processes effectively refine grain structure and boost compactness for carbide turning inserts, eliminating internal pores and unifying grain distribution for stable mechanical performance.

Vacuum liquid-phase sintering is the core mainstream process. It heats inserts to 1320–1600°C to melt cobalt binder evenly, driving WC grain rearrangement and tight bonding. This process fully discharges residual gas inside the blank, removes microscopic pores, and achieves near-theoretical density, forming a fine, compact, uniform grain structure.

Sinter-HIP (hot isostatic pressing) composite sintering further optimizes compactness. It applies uniform high pressure during the high-temperature holding stage to squeeze out closed residual pores that conventional sintering cannot eliminate, refining grain boundaries and greatly improving overall structural densification.

Segmented gradient temperature sintering adopts slow heating + constant-temperature holding + staged cooling. Slow heating ensures uniform atom diffusion and avoids local grain coarsening; precise holding time stabilizes grain size consistency; graded cooling eliminates internal stress, preventing loose grain structures and micro gaps.

Low-temperature long-holding sintering is specially applied to ultra-fine grain turning inserts. It avoids overheating grain growth, maintains tiny and uniform WC grains, and realizes high compactness while preserving the substrate’s balanced hardness and toughness.

These standardized sintering processes collectively reduce insert internal porosity, refine grain uniformity, and enhance structural compactness, directly improving insert wear resistance and impact stability during mass turning production.