Wettability and transient liquid phase bonding of hafnium diboride composite with Ni–Nb alloys
Wettability and transient liquid phase bonding of hafnium diboride composite with Ni–Nb alloys
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DOI：
10.1007/s10853-012-6778-3
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发表时间：
2012-08
影响因子：
4.5
通讯作者：
N. Saito;Hiroyuki Ikeda;Yoshinori Yamaoka;A. M. Glaeser;K. Nakashima
中科院分区：
文献类型：
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作者：
N. Saito;Hiroyuki Ikeda;Yoshinori Yamaoka;A. M. Glaeser;K. Nakashima
为了使超高温陶瓷材料得到更广泛的应用，必须开发出一种适用于超高温陶瓷材料的有效连接方法。采用Ni/Nb/Ni中间层对添加MoSi 2的HfB 2复合材料进行了瞬态液相（TLP）连接，系统研究了TLP连接过程中Ni-Nb合金熔体的润湿行为。此外，还在1，500 °C下进行了具有Ni/Nb/Ni中间层的HfB 2复合材料的试验TLP连接。纯镍被发现熔化在一个温度远低于其正常熔点在加热期间，这主要是由于HfB 2，MoSi 2，和液滴之间的界面反应。所有Ni-Nb合金的接触角均随时间迅速减小，与HfB 2复合材料的润湿性良好。其中，纯Ni液滴在加热过程中在1，400 °C左右完全消失。对润湿样品横截面的SEM-WDS显微结构分析显示，反应层包含涉及Si的多种金属间化合物，表明与烧结助剂MoSi 2的反应。与40 at.% Nb的加入使Ni-Nb合金/HfB 2复合材料界面反应减少。结果表明，采用Ni/Nb/Ni中间层连接HfB 2复合材料时，界面结合良好。
An effective joining strategy suitable for ultra-high temperature ceramics will have to be developed for their wider application. In the present study, the wetting behavior of molten Ni–Nb alloys that will form during the transient liquid phase (TLP) bonding when a Ni/Nb/Ni interlayer is used to bond a HfB2composite processed with MoSi2addition was systematically investigated. In addition, a trial TLP bond of HfB2composite with a Ni/Nb/Ni interlayer was also performed at 1,500 °C. Pure Ni was found to melt at a temperature well below its normal melting point during the heating period, which is mainly attributed to the interfacial reaction between HfB2, MoSi2, and the droplet. The contact angles of all Ni–Nb alloys rapidly decreased with time and showed good wetting against HfB2composite. Among them, the pure Ni droplet totally disappeared around 1,400 °C during heating. SEM–WDS microstructural analysis on the cross section of the wetting sample revealed that the reaction layer contained multiple intermetallic compounds involving Si, suggesting the reaction with the sintering aid MoSi2. With the 40 at.% Nb addition, less interfacial reaction at the Ni–Nb alloy/HfB2composite interface was observed. Consequently, it was revealed that a well-bonded interface was achieved when HfB2composite was bonded using the Ni/Nb/Ni interlayer.