研究了三元Co-20Ni-x Al (x=3,5,质量分数,%)合金在纯氧中800~1000℃下20 h的氧化行为。氧化后,两种合金表面均生成了双层结构外氧化膜,外层膜主要由CoO与少量NiO组成,而内层膜则为CoO与尖晶石的混合物,外氧化膜下为铝的内氧化区。合金...研究了三元Co-20Ni-x Al (x=3,5,质量分数,%)合金在纯氧中800~1000℃下20 h的氧化行为。氧化后,两种合金表面均生成了双层结构外氧化膜,外层膜主要由CoO与少量NiO组成,而内层膜则为CoO与尖晶石的混合物,外氧化膜下为铝的内氧化区。合金的氧化速率随氧化温度的升高而增大;合金中Al含量由3%增加到5%,Co-20Ni-Al合金的氧化速率随之下降,但5%Al仍不足以使合金表面生成保护性的单一氧化铝膜。展开更多
Sn was used to replace Al in Co38Ni34Al28 alloy. The microstructure and microhardness of Co38Ni34Al28-xSnx （x=0, 1, 2, 3） magnetic shape memory alloys were investigated at different heat treatment temperatures （137...Sn was used to replace Al in Co38Ni34Al28 alloy. The microstructure and microhardness of Co38Ni34Al28-xSnx （x=0, 1, 2, 3） magnetic shape memory alloys were investigated at different heat treatment temperatures （1373 K, 1473 K, and 1573 K） for 2 h. The results show that more Sn substitution reduces the content of γ-phase and a partial phase of martensite can be obtained in Co38Ni34Al28-xSnx （x=1, 2, 3） alloys after treatment at 1573 K for 2 h. The maximum martensite phase appears when 2% Al is substituted by Sn. The reverse martensitic transformation temperature of Co38Ni34Al28-xSnx alloys increases at x=1 and 2, then decreases as x=3. As the content of Sn and the temperature increase, the microhardness will increase.展开更多
文摘研究了三元Co-20Ni-x Al (x=3,5,质量分数,%)合金在纯氧中800~1000℃下20 h的氧化行为。氧化后,两种合金表面均生成了双层结构外氧化膜,外层膜主要由CoO与少量NiO组成,而内层膜则为CoO与尖晶石的混合物,外氧化膜下为铝的内氧化区。合金的氧化速率随氧化温度的升高而增大;合金中Al含量由3%增加到5%,Co-20Ni-Al合金的氧化速率随之下降,但5%Al仍不足以使合金表面生成保护性的单一氧化铝膜。
基金Projects (50771037, 50371020) supported by the National Natural Science Foundation of ChinaProject (2011B090400485) supported by the Combination Project for Guangdong Province and the Ministry of Education, China
文摘Sn was used to replace Al in Co38Ni34Al28 alloy. The microstructure and microhardness of Co38Ni34Al28-xSnx （x=0, 1, 2, 3） magnetic shape memory alloys were investigated at different heat treatment temperatures （1373 K, 1473 K, and 1573 K） for 2 h. The results show that more Sn substitution reduces the content of γ-phase and a partial phase of martensite can be obtained in Co38Ni34Al28-xSnx （x=1, 2, 3） alloys after treatment at 1573 K for 2 h. The maximum martensite phase appears when 2% Al is substituted by Sn. The reverse martensitic transformation temperature of Co38Ni34Al28-xSnx alloys increases at x=1 and 2, then decreases as x=3. As the content of Sn and the temperature increase, the microhardness will increase.
