Two intermetallic compounds of Ti-50at.%Al and Ti-48at.%Al-2at.%Cr were prepared with a mechanical alloying and pulse discharge sintering process. The as-sintered material shows a microstructure of equiaxed gamma gra...Two intermetallic compounds of Ti-50at.%Al and Ti-48at.%Al-2at.%Cr were prepared with a mechanical alloying and pulse discharge sintering process. The as-sintered material shows a microstructure of equiaxed gamma grain with sub-micron size. Heat treatments in Vacuum at different temperatures up to 1573 K were conducted on the sintered materials. The microstructure of the material coarsened considerably after heat treatment at temperatures higher than 1523 K. The mechanical properties of the as-sintered and the heat treated materials were measured at temperatures up to 973 K, with four-point bending tests. Experimental results indicate that the addition of Cr increases the fracture strength of the intermetallic compound at room temperature and at elevated temperatures as well. The bending fracture strength increases with increasing testing temperature up to about 873 K and a decrease following up. Both fracture strength and fracture strain of the material were found to be improved by heat treatment. (Edited author abstract) 10 Refs.展开更多
1 Results Direct alcohol fuel cells have been regarded as attractive power sources for portable electric devices. One of the major roadblocks to the implementation of direct alcohol fuel cells is the exploration of th...1 Results Direct alcohol fuel cells have been regarded as attractive power sources for portable electric devices. One of the major roadblocks to the implementation of direct alcohol fuel cells is the exploration of the anode catalyst that can electrochemically oxidize alcohols at lower potentials. Carbon-monoxide (CO) produced through alcohol oxidation deteriorates catalytic activity of Pt, and therefore, the high tolerance for CO poisoning is an important issue to attain high voltage from direct alcoho...展开更多
文摘Two intermetallic compounds of Ti-50at.%Al and Ti-48at.%Al-2at.%Cr were prepared with a mechanical alloying and pulse discharge sintering process. The as-sintered material shows a microstructure of equiaxed gamma grain with sub-micron size. Heat treatments in Vacuum at different temperatures up to 1573 K were conducted on the sintered materials. The microstructure of the material coarsened considerably after heat treatment at temperatures higher than 1523 K. The mechanical properties of the as-sintered and the heat treated materials were measured at temperatures up to 973 K, with four-point bending tests. Experimental results indicate that the addition of Cr increases the fracture strength of the intermetallic compound at room temperature and at elevated temperatures as well. The bending fracture strength increases with increasing testing temperature up to about 873 K and a decrease following up. Both fracture strength and fracture strain of the material were found to be improved by heat treatment. (Edited author abstract) 10 Refs.
文摘1 Results Direct alcohol fuel cells have been regarded as attractive power sources for portable electric devices. One of the major roadblocks to the implementation of direct alcohol fuel cells is the exploration of the anode catalyst that can electrochemically oxidize alcohols at lower potentials. Carbon-monoxide (CO) produced through alcohol oxidation deteriorates catalytic activity of Pt, and therefore, the high tolerance for CO poisoning is an important issue to attain high voltage from direct alcoho...
