Development of a Novel Ni-Based Multi-principal Element Alloy Filler Metal, Using an Alternative Melting Point Depressant
Development of a Novel Ni-Based Multi-principal Element Alloy Filler Metal, Using an Alternative Melting Point Depressant
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DOI：
10.1007/s11661-021-06246-0
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
L. Hardwick;Pat Rodgers;E. Pickering;R. Goodall
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文献类型：
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作者：
L. Hardwick;Pat Rodgers;E. Pickering;R. Goodall
钎焊是镍超合金部件必须连接的行业中的关键连接技术。镍基钎料广泛使用，具有优异的机械性能、耐腐蚀性和高温下的残余强度。为了起到填充金属的作用，合金熔点必须降低到低于被连接材料的熔点，但是添加熔点抑制剂（MPD）如硼、硅和磷会导致脆性金属间化合物的形成，从而潜在地损害接头性能。在本工作中，一种新的多主元素钎焊合金（在高熵合金的风格），利用Ge作为替代MPD沿着与减少B添加，进行了研究。设计过程考虑了二元相图和基于Thermo-Calc软件和经验热力学参数的预测。该合金被用来真空钎焊镍高温合金Inconel-718，和微观组织和力学调查报告。在1100 °C的钎焊温度和60分钟的保持时间下实现的最大剪切强度为297 MPa，其中等温固化完成。剪切强度仅略有减少，增加接缝宽度。利用Thermo-Calc软件和经验热力学参数对多主元素合金性能进行了准确预测。
Brazing is a crucial joining technology in industries where nickel-superalloy components must be joined. Nickel-based brazing filler metals are extensively employed, possessing excellent mechanical properties, corrosion resistance, and retained strength at elevated temperatures. To function as a filler metal, the alloy melting point must be reduced to below that of the materials being joined, but the addition of melting point depressants (MPDs) such as boron, silicon, and phosphorus can, however, lead to the formation of brittle intermetallics, potentially compromising the joint performance. In the present work, a novel multi-principal element brazing alloy (in the style of a high entropy alloy), utilizing Ge as an alternative MPD along with a reduced B addition, is investigated. The design process considered binary phase diagrams and predictions based on Thermo-Calc software and empirical thermodynamic parameters. The alloy was used to vacuum braze nickel-superalloy Inconel-718, and microstructural and mechanical investigations are reported. The maximum shear strength achieved was 297 MPa with a brazing temperature of 1100 °C and 60-minute hold time, with isothermal solidification completed. Shear strength was only slightly reduced with increased joint width. Assessments are made of the ability to accurately predict properties of multi-principle element alloys using Thermo-Calc software and empirical thermodynamic parameters.