Assembling a part made of brittle material

A process for assembling a device including first and second parts made of first and second materials, respectively, and a third part made of a third material that acts as an intermediate part enabling the assembling, the process including: providing a preform made from an at least partially amorphous metal material capable of increasing its volume under temperature and pressure conditions; placing the first and second parts with the preform between two cavity plates having, the negative shape of the device; heating the assembly to a temperature between the glass transition temperature and the crystallization temperature of the preform to enable, at latest during the heating, the preform to be in a form of a foam and enable expansion of the preform to fill the negative shape of the device and form the third part; cooling the assembly to solidify the preform and separate the device from the cavity plates.