The pure Ti, Ni and carbon powders were reaction milled to synthesize the TiC-Ni based cermet powders with ultrafine microstructures. After milling, the ultrafine TiC or amorphous Ti-Ni phase was obtained, respectively, according to the milling condition. The effects of milling variables on the synthesizing behavior of the powders were investigated in detail. The sintered TiC-Ni based cermet of the reaction milled powders consisted of very fine TiC of 0.2~1.5m, as compared with that of a commercial cermet of 3~5m. This demonstrates the potenial of reaction milling as an effective processing route for the preparation of cermet materials.

The effects of the carbon content ranging from 17.5 to 21.0 wt.% in TiC-30vol.% cenmet and the content raging from 0 to 30 wt.% in TiC-20 vol.% cermet were investigated in the relation to the microstures and harbness. The speciment were sintered at 140, 143 and 145 for 60minutes. The results were summarized as follows; 1) The shrinkages and relative densitites of the specimens were incrased up to 20.0 wt.% C and then decreased. 2) The grains of TiC were almost the same size with the different content of carbon. Free carbons were appeared on the microstrures when carbon was added over 20.5 wt.% while TiC and l were formed when carbon was added below 20.0 wt.%; 3) The lattice parameters of the and TiC phases were increased up to 20.5 wt.% C, and then saturated. 4) The hardess was increased up to 20.0 wt.% C, and then decreased. 5) The made the TiC grains fine and the surrounding structure around TiC gains. 6) The micropores were decreased with increasing the binder and the sintering temperature. 7) The lattice parameter of the l ana TiC were almost the samp up to 10 wt.% and then decreased. 8) The hatdness was increased up to 5wt.% and then decreased owing to the micrpores. 9) The more the binder phase, the higher the relative density and the proper amount of cermets were obtained.

NiAl intermetallic compound has been tested as a binder phase, in order to improve the oxidation resistance and the mechanical properties of TiC-Ni cermet at a high temperature. The wettability of on TiC and the optimum sintering condition were investigated in TiC-(30, 40) vol% cermets with the sintering temperature (1380~) and time (30~99 min). The results are summarized as follows: 1) NiAl showed good wettability on TiC above ; 2) The shrinkages of the specimens increased with the sintering temperature, the sintering time and the binder content, whereas the relative densities were decreased; 3) Any other phase did not appeared in the microstructures of all sintered cermets. The grain sizes of TiC became larger as the sintering temperature and the sintering time as well as the binder content increased; 4) The hardness of the cermets decreased with increase in the sintering temperature and the sintering time as well as the binder content; 5) The transverse-rupture strength of the cermets increased with the sintering temperature and the sintering time, whereas it decreased with the binder content.

토란 재배시 종우가 부족할 경우 절편자우를 종우로 활용하는 방법을 연구하고자 본 시험을 실시한 결과는 다음과 같다. 1. 토란의 출현은 절편자우의 크기 별로 차이가 인정되지 않았고, 출현율은 90% 이상 출현되었다. 2. 생육은 절편자우가 클수록 엽병장이 크고 엽병속수가 많아 양호하였다. 3. 토란 절편자우의 크기에 따른 괴경과 부산물인 엽병의 수량은 크기간에 유의성이 인정되어 절편자우가 클수록 수량이 증수되는 경향으로 절편자우 20g을 종우로 사용할 경우 10g당 1,981kg을 생산할 수가 있었다. 이와 같은 결과로 보아 절편자우가 20g 이상인 것을 종우로 사용할 경우 토란의 재배가 가능할 것으로 본다.

토란 재배시 관행적으로 이용가치가 적어서 버리는 설우(屑芋를 종우(種芋)로 활용하는 방법을 연구하고자 본 시험을 실시한 결과는 다음과 같다. 1. 토란의 출현은 종우(種芋)의 크기별로 약간의 차이가 인정되어 자우(子芋)인 설우(屑芋)나 소우(小芋)가 친우(親芋)보다 약간 빠른 경향이었으나 출현율은 친우가 높았다. 2. 생육은 자우(子芋)보다는 친우가 엽병장이 크고 엽병속수(葉炳束數)가 많아 양호하였으며, 자우(子芋)가 클수록 생육이 양호한 경 향이었다. 자우(子芋)중 설우(屑芋)도 엽병속이 1.5~2.6개 발생되어 정상적인 생장이 가능하였다. 3.토란 종우(種芋)의 크기에 따른 괴경(塊莖)과 부산물(副産物) 엽병(葉炳)의 수량은 자우(子芋)의 크기간에 차이가 인정되어 자우(子芋)가 클수록 수량이 증수되는 경향이었다. 또한 설우(屑芋)도 크기에 따라 10a 당730~1,680kg의 괴경(壞莖)과 100~310kg의 엽병(葉炳)을 생산할 수가 있어서 대면적의 재배시 종우(種芋)로 이용이 가능할 것으로 생각된다.