Oxide Additives in COM‐ABS Modified Glass: Effects on Material Properties and Mechanism of Enhanced Joining With RB‐SiC

Reaction‐bonded silicon carbide (RB‐SiC) is a key material for semiconductor vacuum chucks, yet its reliable joining at low‐to‐medium temperatures remains challenging. Using a single‐factor deletion method, Na 2 O, CaO, MgO, and CeO 2 were introduced into an Al 2 O 3 ‐(K 2 O‐Li 2 O)‐B 2 O 3 ‐SiO 2 (ABS) glass matrix to systematically investigate their individual and synergistic effects. As the primary network modifier and fluxing agent, Na 2 O significantly reduces melt viscosity and wetting angle while promoting [BO 3 ] to [BO 4 ] conversion. CaO forms Ca─O─Si chemical bridges at the interface and raises crystallization temperature, while MgO fine‐tunes thermal expansion and improves stability. CeO 2 enhances thermal stability and wettability but relies on Na + for charge compensation. The fully supplemented composition (Sample A) showed optimal performance, achieving a shear strength of 83 MPa at 900°C—a 189% increase over the unmodified glass (Sample Raw). This improvement is attributed to a fundamental change in the interfacial bonding mechanism, as well as a composite reaction layer composed of nanocrystals, residual SiC, and an infiltrated glass phase, which together create a mechanical interlocking structure. At 950°C, the mechanism evolved from a “reaction‐dominated heterogeneous nucleation” mode to a “diffusion‐dominated epitaxial growth” mode, with controlled β‐quartz solid solution precipitation further increasing strength to 107 MPa. This study clarifies the distinct roles of each additive and demonstrates that multicomponent design enables precise regulation of thermal, wetting, and interfacial properties, offering a systematic strategy for high‐performance RB‐SiC joining.