Evaluation of Pd-based brazes to join silicon nitride to copper-clad-molybdenum

Si3N4 (SN-281)/Cu-clad-Mo joints, brazed using a soft (YS: 341 MPa) and ductile (43% elongation) Pd–Co braze were sound and exhibited an interaction zone comprised of Pd66Mo14Cu10Co6Si3 and Pd74Mo11Co8Cu6Si. Similar joints made using a less ductile and stronger Pd–Ni braze led to cracking from large CTE mismatch-induced strain energy (∼64 mJ to 348 mJ).