摘要
利用Ｃｕ－３９％Ｎｉ－６％Ｆｅ和Ｎｉ－３０％Ｃｕ－５％Ｆｅ（ｗｔ％）两种合金研究了在不同配方坩埚烧结涂层中合金液冷却时的过冷度。结果表明，（８０％石英砂＋２０％石英玻璃粉）＋３％Ｈ３ＢＯ３坩埚涂层材料，在以石墨为发热体的高频感应炉中１９２３Ｋ温度下烧结后，可获得３ｍｍ厚表面光洁、无裂纹的玻璃态涂层。在该涂层中熔炼上述两种合金，分别获得了１９０Ｋ和２１０Ｋ的大过冷度，超过了两种合金晶粒骤然细化的临界过冷度ΔＴ＊２。
Owing to several reasons, rapidly solidified samples of highly undercooled CuNiFe alloy weighed only several grams each. We prepared special sintered coatings that make possible such rapidly solidified samples weighing several tens of grams or more each. The undercooling capabilities of Cu-39%Ni-6%Fe and Ni-30%Cu-5%Fe alloys in the specially coated crucibles were investigated by using glass flux and thermal cycling technologies. The experimental results indicate that the best coating material of sintered crucible consists of (80%silica sand +20%fused silica powder)+3%H 3BO 3. With high purity graphite as heater, a fine glass layer (≥3 mm) without any crack was obtained under 1 923 K sintering temperature in an induction furnace. In the specially coated crucible, Cu-39%Ni-6%Fe and Ni-30%Cu-5%Fe alloys were undercooled to 190 K and 210 K respectively, which exceed their critical undercooling limits at which the microstructures of the alloys change abruptly from dendrite to fine spherical grains.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1999年第1期48-52,共5页
Journal of Northwestern Polytechnical University
关键词
深过冷
坩埚涂层
熔体
烧结涂层
铜镍铁合金
CuNiFe alloys, high undercooling, critical undercooling limit, crucible coating
