Chapter 6 - Reaction Sintered SiC (RSSC)

Abstract

Reaction-sintered silicon carbide (RSSC), also known as reaction-bonded silicon carbide (RBSC), and as siliconised silicon carbide is a cermet in which SiC is the continuous phase (>75%) and silicon the discontinuous phase (<25%). Its invention was a very slow evolutionary process from the 1910s to the 1960s, RSSC is one of the earliest types of SiC ceramics invented, predated only by glass-bonded SiC (GBSC). RSSC is the best SiC type in terms of the cost-benefit analysis or ‘bangs per buck’. High-quality RSSC can perform equally well as DSSC in ballistic armour and comes close to DSSC in wear-resistance applications, but RSSC has half the manufacturing cost of DSSC since RSSC is manufactured from cheap abrasive grades of SiC, rather than the costly submicron highly refined SiC powders required for DSSC. The dearth of information in the scientific literature on RSSC, and the complexity of its manufacturing process, make it difficult to reverse engineer RSSC, which presents a high barrier for entry to new players in RSSC manufacturing. RSSC is a net shape process (unlike DSSC) which enables excellent manufacturing tolerances. The principal use of RSSC is as a wear-resistant ceramic, and secondarily as an armour ceramic. This chapter gives a detailed overview of RSSC ceramics, beginning with their history and then exploring their evolution, The RSSC manufacturing process is then comprehensively reviewed based on the author’s many years of experience in industrial production of RSSC as a wear-resistant and armour ceramic, providing the most detailed exposition that the author is aware of on the RSSC technology. This is from science, engineering, and manufacturing perspective. Siliconised boron carbide, a spin-off technology currently under development, is also briefly discussed in this chapter, as is siliconised graphite.