Novel Active Soldering; Creating Enhanced joints Near-ambient Temperature (NASCENT)

新颖的活性焊接；

• 批准号: EP/V050788/1
• 负责人: Russell Goodall
• 金额: $ 27.07万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV050788%2F1
• 关键词: Novel; Active; Soldering; Creating; Enhanced

The creation of new, 21st Century manufactured products gives us exciting possibilities. However, the number of complex devices and components that consist of one piece of a single material is negligible; almost all manufacturing involves the joining of materials.Joining technology is extensive, but is still challenged by novel designs and new advanced materials. Frequently, these needs could be met by soldering, where a low melting point alloy is introduced in liquid form into the joint, where it solidifies, making a bond. Many people will associate soldering with the electronics industry, where it is widely used, reliably, effectively and at low cost.Yet current soldering is not good at forming bonds with many materials, (for example metals with tenacious oxides and ceramics) and it does not form strong joints which can resist exposure to elevated temperatures where applications demand it. To do this may need an approach used for brazing (very much like soldering, but at higher temperature) of adding an element to the alloy, whose role is to chemically interact with surfaces and improve wetting when liquid and bonding once solidified. Adapting the terminology from brazing, this would be "active soldering".Such a process is not simple however. First we must identify the correct active elements, which may not be the ones used in brazing. These must produce sufficient reaction at low temperatures and be adapted to the materials being bonded. Secondly, a way to introduce a large enough amount of these elements into the solder is required. Solders are based on tin, which may react with the active elements itself if too large quantities are present. Finally, such joints that have been attempted have very poor mechanical properties, and these must be improved.To resolve these challenges, we will deposit the active elements (selected with the aid of thermodynamic modelling) onto a metallic carrier, a Ni or Cu sponge or foam, with fine (~0.5mm) pores, and infiltrate the Sn into this, creating a composite solder. This will keep the active elements and the Sn separate until soldering, when the Sn will begin to dissolve the foam and progressively release the active material to aid in bonding. The residual network of the foam structure across the joint seam will also be effective in increasing the joint strength. We will make and test these composite solders and the joints, and we will also probe the reactions occurring in great detail, to ensure we understand the key step of this new technology.Of immediate use, this approach will improve the strength of bonds achieved in current applications (such as in antennae, heat exchangers and semiconductor devices), give them higher temperature resistance in service and reduce the environmental impact of the process, by removing the need for polluting chemical fluxes or electroplating to prepare the joint and aid bonding. The benefits certainly do not stop there, as the technology would also allow new applications. For example, metals like stainless steel are brazed in vacuum at high temperature; achieving the same goal at lower temperatures and in air would be a much less expensive process. Low process temperatures save energy and cost; for example, some electroceramics (important for, e.g. capacitors) can be processed by cold sintering at temperatures as low as 200degC, but the advantages would be lost without low temperature means to join them in electronic devices. Advanced materials such as graphene also hold much promise in areas like touchscreens and circuitry, and a technique like that developed here would be an essential part of making this a reality.The simple, mass manufacturing nature of solder means that, with our research partners including end users and processors of solder materials, the scalability of the new method created, and the chances of realising these benefits, will be very high.

新的，21世纪的制造产品的创造给我们带来了令人兴奋的可能性。然而，由单一材料组成的复杂设备和组件的数量可以忽略不计；几乎所有的制造都涉及材料的连接。连接技术是广泛的，但仍然受到新的设计和新的先进材料的挑战。通常，这些需求可以通过焊接来满足，在焊接中，将低熔点合金以液体形式引入接头，在那里凝固，形成键。许多人会将焊接与电子工业联系起来，在那里它被广泛使用，可靠，有效和低成本。然而，目前的焊接并不擅长与许多材料（例如具有强氧化物的金属和陶瓷）形成键合，也不能形成坚固的接头，无法抵抗高温下的应用要求。要做到这一点，可能需要一种用于钎焊的方法（很像焊接，但在更高的温度下），即在合金中添加一种元素，其作用是与表面发生化学反应，改善液体时的润湿性，并在凝固后进行粘合。适应术语从钎焊，这将是“主动焊接”。然而，这个过程并不简单。首先，我们必须确定正确的有效元素，这些元素可能不是钎焊中使用的元素。它们必须在低温下产生足够的反应，并适应所粘合的材料。其次，需要一种将足够多的这些元素引入焊料的方法。焊料是基于锡的，如果存在太多的活性元素，锡可能与活性元素本身发生反应。最后，已经尝试过的这种接头具有非常差的机械性能，必须加以改进。为了解决这些挑战，我们将活性元素（在热力学建模的帮助下选择）沉积到金属载体上，Ni或Cu海绵或泡沫，具有细小（~0.5mm）的孔隙，并将Sn渗透到其中，形成复合焊料。这将保持活性元素和锡分离，直到焊接，这时锡将开始溶解泡沫，并逐步释放活性物质，以帮助粘合。泡沫结构在接缝上的残余网络也将有效提高接缝强度。我们将制作和测试这些复合焊料和接头，我们还将非常详细地探索发生的反应，以确保我们了解这项新技术的关键步骤。立即使用，这种方法将提高当前应用（如天线，热交换器和半导体设备）中实现的键合强度，使其在使用中具有更高的耐温性，并减少该过程对环境的影响，因为不需要污染化学助焊剂或电镀来制备接头和辅助键合。好处当然不止于此，因为这项技术还将允许新的应用。例如，不锈钢等金属是在真空中高温钎焊的；在更低的温度和空气中实现同样的目标将是一个更便宜的过程。工艺温度低，节约能源和成本；例如，一些电陶瓷（对电容器等很重要）可以在低至200摄氏度的温度下通过冷烧结进行加工，但如果没有低温手段将其加入电子设备中，其优势就会丧失。石墨烯等先进材料在触摸屏和电路等领域也很有前景，而这里开发的这种技术将是实现这一目标的重要组成部分。焊料的简单，大规模制造性质意味着，与我们的研究合作伙伴，包括焊料材料的最终用户和处理器，新方法的可扩展性和实现这些好处的机会将非常高。

项目成果

Design of higher temperature copper brazing filler metals with reduced brittle phase content

降低脆性相含量的高温铜钎料设计

• DOI: 10.1016/j.mtcomm.2023.105524
• 发表时间: 2023
• 期刊: Materials Today Communications
• 影响因子: 3.8
• 作者: Hardwick L

Development of low-temperature active solders

低温活性焊料的开发

• 发表时间: 2022
• 作者: Hardwick L

High Entropy Alloys as Filler Metals for Joining.

• DOI: 10.3390/e23010078
• 发表时间: 2021-01-07
• 期刊: Entropy (Basel, Switzerland)
• 作者: Luo D;Xiao Y;Hardwick L;Snell R;Way M;Sanuy Morell X;Livera F;Ludford N;Panwisawas C;Dong H;Goodall R
• 通讯作者: Goodall R

Microstructure transformation and mechanical properties of Al alloy joints soldered with Ni-Cu foam/Sn-3.0Ag-0.5Cu (SAC305) composite solder

泡沫Ni-Cu/Sn-3.0Ag-0.5Cu(SAC305)复合焊料焊接铝合金接头的组织转变及力学性能

• DOI: 10.1016/j.jallcom.2022.166135
• 发表时间: 2022
• 期刊: Journal of Alloys and Compounds
• 影响因子: 6.2
• 作者: Xiong C

In-situ observations of spreading behaviour of SAC305 solder on silver and copper substrates

SAC305 焊料在银和铜基材上的铺展行为的现场观察

• 发表时间: 2022
• 作者: Olukoya O