| Title |
Resistance / Spark Sintering under Pressure of Intermetallic TiAl Powders |
| Authors |
최국선(Good Sun Choi); 김진영(Jin Young Kim); 이동희(Dong Hi Lee) |
| Abstract |
The effects of current density and the mode of applied current(DC and/or AC) on the resistance/spark sintering of TiAl powders were investigated to develope a new consolidation technique for this intermetallic compound. PREPed r-TiAI powders ranging 180∼210㎛ in size were sintered for short time of period(∼2mins) applying two different pressure by step by step during the flow of high density current of DC and/or AC. It was found that the mixed mode of DC+AC was more effective for the densification than DC mode because the former mode was believed to allow TiAl powders inside graphite dies to reach higher temperature due to the sparking at the neck area and uniform current distribution in the powder compact by AC effects. Compacts of high relative density($gt;99%) and uniform lamellar structure were obtained at the condition of DC(540A/㎠)+AC(50 A/㎠ and 5 ㎑). |