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The effect of carbon addition on microstructural evolution was studied in a near-αtitanium alloy (Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.7Nd). It was found that flake and ribbon titanium carbides with a NaCl crystal structure formed in the as-cast alloys with carbon additions of over 0.17 wt pct. Flake carbide particles are the product of eutectic transformation and precipitate from the high-temperatureβphase. The ribbon carbide particles are primary phases formed prior to the nucleation of any metallic phases. The as-cast alloys with carbide precipitation after heat-treatment atβt-30℃followed by water quenching showed the spheroidization ofαlamellae and partial dissolution of carbide particles. After annealing atβt+15℃, carbide particles are mostly distributed at the grain boundary and spheroidized through mixed grain boundary plus bulk diffusions.
The effect of carbon addition on microstructural evolution was studied in a near-αtitanium alloy. (Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.7Nd). It was found that flake and ribbon titanium carbides with a NaCl crystal structure formed in the as-cast alloys with carbon additions of over 0.17 wt pct. Flake carbide particles are the product of eutectic transformation and precipitate from the high-temperature βphase. The ribbon carbide particles are primary phases formed prior to the nucleation of any metallic phases. The as-cast alloys with carbide precipitation after heat-treatment at βt-30 ° C followed by water quenching showed the spheroidization of αlamellae and partial dissolution of carbide particles. After annealing atβt + 15 ° C, carbide particles are mostly distributed at the grain boundary and spheroidized through mixed grain boundary plus bulk diffusions