NaCl和KClO3含量对盐助燃烧合成的NiTi粉体组成和结构的影响
2015-07-10王小翠喇培清李贤明欧玉静魏玉鹏孟倩
王小翠 喇培清 李贤明 欧玉静 魏玉鹏 孟倩



摘 要:盐助燃烧合成制备了不同NaCl和KClO3含量的NiTi合金粉末,采用XRD、SEM和EDS等方法对NiTi合金的组成和结构进行表征,并分析了不同NaCl和KClO3含量对NiTi粉体组成和结构的影响及其作用机制。结果表明,随NaCl含量的增加,NiTi、Ni4Ti3相组成比例发生不同的变化,其中10%(wt)NaCl中NiTi相含量最高为92%。随KClO3含量的增加,粉体中Ni4Ti3和TiO2的含量大幅增加,5%(wt) KClO3中Ni、Ti原子比最佳为0.79:1。粉碎后的NiTi粉末,具有形状不一的颗粒形貌和较宽的粒度分布范围。不同NaCl含量的粉末粒度基本保持不变,在950 nm左右,而不同KClO3含量的NiTi材料的平均粒度随其含量的增加而减小。
关 键 词:NiTi粉体;盐助燃烧合成;稀释剂NaCl;助燃剂KClO3
中图分类号:TG 146 文献标识码: A 文章编号: 1671-0460(2015)09-2061-05
Abstract: NiTi alloy with different addition of NaCl and KClO3 was prepared by salt-assisted combustion synthesis. Its composition and phase structure were investigated by X-ray diffractometry, scanning electron microscopy and energy dispersive spectroscopy. The influence and action mechanism of different NaCl and KClO3 content on the constitution and structure of NiTi powder were studied. The results show that NiTi and Ni4Ti3 have different composition with increase of NaCl content,and the powder with 10%(wt) NaCl has the maximum NiTi of 92%.With the increase of KClO3 content, the content of Ni4Ti3 and TiO2 increase significantly, whereas NiTi decreases. the powder with 5%(wt) KClO3 has the best ratio of Ni/Ti with 0.79:1.NiTi powder has inhomogeneous morphology and wide particle size distribution. NaCl content has little influence on the particle size, whereas the particle size decreases with the increase of KClO3 content.
Key words: NiTi powder ; SACS; Diluent agent NaCl; Heating agent KClO3
Ni-Ti系形状记忆合金因其良好的力学性能,如抗疲劳、耐磨损、抗腐蚀及形状记忆恢复率高和生物相容性好而被广泛应用于电子、航空航天、机械及生物领域[1-4]。比如,其高机械阻尼特性被使用在飞行器,楼房及桥梁等的减震器件中[5, 6]。同时,NiTi合金制备的生物医学植入体在骨科,牙科和心血管外科等领域已经得到了大量应用,是目前唯一用作生物医学材料的形状记忆合金[7]。而且NiTi粉体可作为原始粉末被应用于3D打印技术[8]。
NiTi合金因其杰出的应用性能而被广泛研究,也已经发展出多种制备NiTi合金的方法。现有的NiTi的制备方法有热压烧结[9],预合金粉末烧结法[10],超高压合成法[11], 大塑性变形法[12],不封装热等静压法[13],它们的缺点是过程及设备复杂,能源消耗大,而自蔓延燃烧合成法[14-16]是应用最广的一种方法。……
