ʻO ka seramika alumina pale-ʻaʻahu: nā waiwai, ka hana ʻana, a me nā noi

ʻO ka keramika alumina kūpaʻahe mea keramika ʻoihana holomua i haku ʻia me ka alumina maʻemaʻe kiʻekiʻe (Al₂O₃). Ua lilo ia i mea nui no ka hoʻoponopono ʻana i ka ʻaʻahu koʻikoʻi, ka pala, a me nā kūlana wela kiʻekiʻe ma muli o kona paʻakikī koʻikoʻi, ke kūpaʻa ʻana i ka ʻaʻahu, a me ke kūpaʻa kemika. Ke hoʻohālikelike ʻia me nā mea pale ʻaʻahu metala kuʻuna, hoʻolōʻihi nui ia i ke ola lawelawe lako a hoʻemi i ka pinepine o ka mālama ʻana a me nā kumukūʻai ma nā ʻāpana ʻoihana he nui, e lawelawe ana ma ke ʻano he hopena koʻikoʻi no nā ʻoihana mai ka ikehu a me ka metallurgy a hiki i ka hana kiʻekiʻe.

Hoʻokumu ʻia kāna hana kūikawā ma luna o ka ʻikepili kino a me ke kemika pololei. Hiki i ka paʻakikī Rockwell (HRA) o ka alumina ceramic ke hiki i 80-90, me ka ikaika compressive e ʻoi aku ana ma mua o 850 MPa. Hōʻike nā hoʻokolohua ʻoihana i kona kūpaʻa ʻana i ka ʻaʻahu he 266 mau manawa o ke kila manganese a me 171.5 mau manawa o ka hao i hoʻolei ʻia me ka chromium kiʻekiʻe. No ke kūpaʻa ʻana i ka mahana, hiki i kona mahana lawelawe lōʻihi ke hiki i 300°C, a hiki iā ia ke kū i ka pala waikawa a me ka alkali i loko o kahi pae pH o 3 a 12. ʻO kēia mau waiwai e hiki ai iā ia ke hana paʻa i nā wahi hopena kiʻekiʻe, ʻaʻahu kiʻekiʻe, a me nā ʻino, no ka laʻana, e hoʻolōʻihi ana i ke ola lawelawe o nā paipu lawe pauka lanahu ma mua o 10 mau manawa.

ʻO ka hana o ka keramika alumina pale ʻaʻahu e pōmaikaʻi mai ka kaohi pololei ʻana o ke kaʻina holoʻokoʻa mai nā mea maka a hiki i ka sintering. ʻO ka mea mua, ua hana ʻia ka pauka alumina maka i ka wili maikaʻi loa, me ka nui o ka ʻāpana i kāohi pinepine ʻia ma lalo o 1 micron, e hōʻoiaʻiʻo ana i ka maʻemaʻe kiʻekiʻe a me ka hoʻolaha like ʻana o ka nui o ka ʻāpana. ʻO nā kaʻina hana hoʻokumu mua e pili ana i ke kaomi maloʻo a me ke kaomi isostatic, ʻo ka mea hope e hāʻawi ana i ka nui like i ke kino ʻōmaʻomaʻo. ʻO ka hope, ua sintered ʻia ke kino ʻōmaʻomaʻo ma kahi o 1700°C, e hana ana i kahi ʻano microcrystalline paʻa, me ka nui o nā mea e hiki aku ana ma luna o 95%. Hiki i nā ʻano hana hui, e like me ka hoʻohui ʻana i ka zirconia (ZrO₂), ke hoʻonui hou aku i kona kūpaʻa i ka hopena a me ka paʻakikī.

Hoʻohana nui ʻia kēia mea ma nā ʻāpana ʻoihana he nui. I loko o nā ʻoihana ikehu a me ka palekana o ke kaiapuni, hoʻohana ʻia ia i loko o nā paipu pauka lanahu o nā mea kanu mana wela, a i loko o nā mea hoʻokaʻawale a me nā cone cyclone o nā mea kanu sima, e hoʻonui ana i ke ola lawelawe o nā lako ma 3 a 5 mau manawa. I loko o nā ʻoihana metallurgy a me ka mining, ʻo nā liners keramika i hoʻokomo ʻia i loko o nā paipu injection lanahu umu pahū a me nā pipeline wehe lepo e kūʻē pono i nā mea hoʻoheheʻe nui e like me ka pauka hao, e hōʻemi ana i nā kumukūʻai mālama makahiki a hiki i ka 60%. Eia kekahi, hoʻohana ʻia nā keramika alumina maʻemaʻe kiʻekiʻe loa (e laʻa, 99.7%) i nā kahua hana kiʻekiʻe e like me ka semiconductor wafer polishing.