Stoichiometric Si3N4 has an estimated shear modulus of about 119 GPa. Be
careful, however, because LPCVD silicon nitride can be made in various
atomic ratios - some with oxygen. You may wish to have your particular
material measured by obtaining the transverse and longitudinal velocities of
sound and computing the various moduli from them.
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.