Abstract
High melting point intermetallic compounds are potential candidates for ultra-high temperature structural materials for aerospace and energy. Nb3Al has been being developed in the MITI's "high performance materials for severe environments project". This project started as an eight-years national project in 1989. Nb3Al has a high melting temperature, 2233K, and ordered A15 structure. Due to the crystal structure, this compound exhibits limited ductility and limited workability. Powder metallurgical processing, especially using the rapidly solidified powder for the starting material, must be useful for preparation of this brittle compound. For the production of the Nb3Al powder, a new gas-atomizing technique has been developed. By using the gas-atomizing pilot plant that has the pressurized plasma furnace with the melting capacity of 10kg of Nb3Al, the rapidly solidified Nb-Al powders have been produced. The produced powders consist of supersaturated solid solution of Al in Nb (bcc) and possess good compactibility. These powders were consolidated by HIP, and the high temperature strength was estimated for the consolidated bodies. Furthermore, we began to develop the technique for in-situ measurement and control of the powder size distribution during atomization.
