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纳米金属丝具有优越的敏感性、场发射效能、超强的记忆功能等特性,于是对它的研究便备受青睐。通过定向凝固NiAl-Re复相共晶,再结合选择性溶解或腐蚀的方法来制备Re纳米丝,即DSW技术。利用Bridgman定向凝固设备对NiAl-1.5at%Re共晶合金进行定向凝固,在约300K/cm的温度梯度条件下,通过改变凝固抽拉速率获得不同的NiAl-Re准共晶组织,研究分析了NiAl-Re共晶的显微结构、凝固速率与纤维相间距、纤维大小的相关性。发现随着凝固速率的增大,纤维相间距和纤维尺寸都逐渐减小,并且两者与凝固速率的平方满足良好的线性关系。使用HCl:H2O2的蒸馏水稀释溶液对NiAl基体进行选择性腐蚀,这一过程会形成对共晶体的各向异性腐蚀,在被腐蚀的表面上会出现直径为450～500nm、长度不一的铼纤维丝。腐蚀得到的Re纳米丝可望应用于纳米电极阵列中。
Nano-wire with superior sensitivity, field emission efficiency, superior memory function and other characteristics, so its research will be highly favored. The Re nanowires, namely the DSW technique, are prepared by directional solidification of NiAl-Re complexed eutectic followed by selective dissolution or etching. The Bridgman directional solidification equipment was used to directionally solidify the NiAl-1.5at% Re eutectic alloy. Different NiAl-Re pseudo-eutectic structures were obtained by changing the solidification drawing speed at a temperature gradient of about 300K / cm. Microstructure of NiAl-Re eutectic, solidification rate and fiber spacing, fiber size correlation. It is found that with the increase of the solidification rate, the fiber spacing and the fiber size decrease gradually, and both of them satisfy the good linear relationship with the square of the solidification rate. Selective etching of the NiAl matrix with a dilute solution of HCl: H 2 O 2 in distilled water results in anisotropic corrosion of the eutectic. A rhenium fiber of 450 to 500 nm in diameter and varying in length appears on the etched surface wire. Corrosion of Re nanowires is expected to be used in nano-electrode arrays.