PURPOSE: To provide the method for forming an article by explosive bonding two or more components together to form superplastically a composite article and superplastically secondary forming the resulting article.

CONSTITUTION: The explosive bonding involves spreading a layer of salt 12 between components and an anvil 10 to prevent the components bonding to the supporting structure 10 (anvil) during the explosion, and coating the external surface of the components with an adherent elastic coating (26, 28) to prevent surface degradation during the explosion.