US 6586704 B1 abstract a method for diffusion bonding ceramic layers such as boron carbide zirconium carbide or silicon carbide uses a defocused laser beam to heat and to join ceramics with the use of a thin metal foil insert the metal foil preferably is rhenium molybdenum or titanium the rapid intense heating of the ceramic metal ceramic sandwiches using the defocused laser beam results in diffusive conversion of the refractory metal foil into the ceramic and in turn creates a strong bond therein application_number US 85455101 A description ceramic metal ceramic constructs are diffusion bonded according to the invention using a defocused laser fig1 is a schematic diagram which illustrates that within an inert atmosphere in a u201c glove box u201d known in the art a defocused laser beams into a ceramic metal ceramic sandwich clamped to a base plate the heat of the laser joins the sandwich layers without appreciable melting of the metal to create a diffusion bond most preferably the foil s are rhenium or molybdenum between about 12 and 25 u03bcm in thickness the process is conducted in a glove box containing a purified inert atmosphere preferably argon with less than 1 part per million each of oxygen nitrogen and moisture many varieties of ceramics may be bonded according to the present method including but not limited to silicon carbide sic zirconium carbide.