Estudo da síntese e sinterização de pós compósitos do sistema Ta-Cu

AUTOR(ES)

José Ferreira da Silva Júnior

DATA DE PUBLICAÇÃO

2008

RESUMO

Ta-Cu bulk composites combine high mechanical resistance of the Ta with high electrical and thermal conductivity of the Cu. These are important characteristics to electrical contacts, microwave absorber and heat skinks. However, the low wettability of Ta under Cu liquid and insolubility mutual these elements come hard sintering this composite. High-energy milling (HEM) produces composite powders with high homogeneity and refines the grain size. This work focus to study Ta-20wt%Cu composite powders prepared by mechanical mixture and HEM with two different conditions of milling in a planetary ball mill and then their sintering using hydrogen plasma furnace and a resistive vacuum furnace. After milling, the powders were pressed in a steel dye at a pressure of 200 MPa. The cylindrical samples pressed were sintered by resistive vacuum furnace at 10-4torr with a sintering temperature at 1100C / 60 minutes and with heat rate at 10C/min and were sintered by plasma furnace with sintering temperatures at 550, 660 and 800C without isotherm under hydrogen atmosphere with heat rate at 80C/min. The characterizations of the powders produced were analyzed by scanning electron microscopy (SEM), x-ray diffraction (XRD) and laser granulometry. After the sintering the samples were analyzed by SEM, XRD and density and mass loss tests. The results had shown that to high intense milling condition produced composite particles with shorter milling time and amorphization of both phases after 50 hours of milling. The composite particles can produce denser structure than mixed powders, if heated above the Cu melting point. After the Cu to arrive in the melting point, liquid copper leaves the composite particles and fills the pores

ASSUNTO(S)

compósitos ta-cu ta-cu composites sintering immiscible system moagem de alta energia sistemas imiscíveis ciencias exatas e da terra sinterização high-energy milling

Documentos Relacionados

• Estudo da moagem de alta energia e sinterização de pós compósitos W-Cu
• Síntese em uma etapa e microestrutura de compósitos CuO-SDC
• ESTUDO DA CINÉTICA DE SINTERIZAÇÃO DO SISTEMA SnO2.ZnO
• Calculo termodinamico do sistema Fe-Nb e estudo experimental do sistema Fe-Ta
• Estudo experimental do sistema Ta-Ge e da região rica em Ta do ternário Ta-Ge-B