Evaluation of mechanical alloying to obtain Cu-Al-Nb shape memory alloy

• Autor(a) principal: Silva,Maria do Carmo Amorim da
• Data de Publicação: 2005
• Outros Autores: Lima,Severino Jackson Guedes de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Materials research (São Carlos. Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392005000200014
• topic: powder metallurgy; mechanical alloying; sintering

The technical viability of preparing a Cu-Al-Nb shape memory alloy by high energy ball milling in a planetary mill has been evaluated. The alloy Cu-13Al-2Nb (wt. (%)) was prepared by mixing pure elemental powders. A ball-to-powder weight ratio of 6:1 and rotation rate of 150 rpm in argon atmosphere were the main processing parameters. The milling time ranged from 1 to 65 hours. Changes in microstructure as a function of milling time were investigated, using X-ray diffraction analysis and scanning electron microscopy. To investigate the viability of producing sintered parts from milled powders, the conventional powder metallurgy route was used. The milled powders were compacted in a cylindrical die at 900 MPa. Sintering was carried out in argon atmosphere at 850 °C for 6 hours. This study has shown that high energy ball milling, combined with pressing and sintering, can be used to promote the formation of a copper-aluminum solid solution and achieve final sintered densities of 91% of the theoretical density.