Abstract: A method for achieving both improved high strength and improved ductility in intermediate phases is provided. The method, briefly stated, comprises the steps of providing a melt whose composition substantially corresponds to that of a preselected intermetallic phase having a crystal structure of the L1.sub.2 type, such as nickel aluminide, modified with from about 0.01 to 2.5 atomic percent boron, and rapidly solidifying the melt at a cooling rate of at least about 10.sup.3 .degree. C./second to form a solid body, the principal phase of which is of the L1.sub.2 type crystal structure in either its ordered or disordered state.