Transient liquid phase, pressureless joining of aluminum nitride components

A process for joining ceramic components, said process comprising:

• selecting at least two green state aluminum nitride (AlN) particle components having different aspect ratios,
• and containing an amount of a transient liquid phase inducing additive comprising a first rare earth oxide in a concentration of about 1-5% by weight of the AlN present,
• each of said components having a contact area shaped and dimensioned to intimately contact the contact area of an other of said components when said components are matingly contacted to one another;
• placing said components in mating contact in a substantially contained atmosphere;
• co-heating said components to a form a transient liquid phase along said contact areas for about 60 to 300 minutes;
• allowing a vaporized amount of said first rare earth oxide to form in said substantially contained atmosphere, wherein said vaporized amount has a partial pressure of no more than about 1.0 atmosphere, thereby substantially pressurelessly inhibiting further vaporization of said transient liquid phase during said co-heating;
• and,
• cooling said components to room temperature.