Structural Evaluation of Mechanically Alloyed Ti-Nb Powders

Autor(es)

Giffoni, Y. A. ; Ramos, E. C. T. ; Sandim, H. R. Z. ; Pacheco, M. T. T. ; Silva, G. ; Ramos, A. S. ; Salgado, L ; filho, FA

• Tipo de documento: Artigo Científico
• Fonte: Materials Science Forum; v. 591-593, p. 2-pg., 2008-01-01.

Resumo

This work discusses on the structural evaluation of mechanically alloyed Ti-Nb powders. The Nb amount was varied between 20 and 50 wt-%. The milling process was carried out in a planetary Fritsch P-5 ball mill under Ar atmosphere. The structural evaluation was conducted by scanning electron microscopy, X-ray diffraction, and energy dispersive spectrometry. During ball milling it was noted an excessive agglomeration of ductile Ti-Nb powders on the balls and vial surfaces, and the final amount of remaining powders was then drastically reduced into the vials. This fact was more pronounced with the increased Nb amount in starting powders. Typical lamella structures were formed during ball milling, which were refined for the longest milling times, and fine and homogeneous structures were formed in Ti-Nb (Nb=20-50wt-%) powders. XRD results indicated that the full width at half maximum values of Ti peaks were continuously increased while that the crystallite sizes were reduced for longer milling times due to the severe plastic deformation provided during ball milling of Ti-Nb powders. However, the EDS analysis revealed the presence of Nb-rich regions in Ti-Nb powders after ball milling. The critical ball milling behavior of ductile Ti-Nb powders contributed for reducing the yield powder and increasing the structural heterogeneity. (AU)

• Processo FAPESP: 02/01400-8 - Estudo sobre a produção de pós via moagem de alta energia de ligas do sistema Ti-Si-B
• Beneficiário: Alfeu Saraiva Ramos
• Modalidade de apoio: Bolsas no Brasil - Jovens Pesquisadores
• Processo FAPESP: 01/07025-1 - Estudo sobre a produção de pós via moagem de alta energia de ligas do sistema Ti-Si-B
• Beneficiário: Alfeu Saraiva Ramos
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 99/09327-3 - Avaliação experimental da seção isotérmica a 1750ºC e determinação da projeção liquidus na região rica em Ta do sistema Ta-B-Si
• Beneficiário: Erika Coaglia Trindade Ramos
• Modalidade de apoio: Bolsas no Brasil - Doutorado