Brazeability of similar hybrid joint compounds consisting of additively manufactured and conventional material grades

由增材制造和传统材料等级组成的类似混合接头化合物的可钎焊性

• 批准号: 407147480
• 负责人: Professor Dr.-Ing. Wolfgang Tillmann
• 金额: --
• 依托单位: Lehrstuhl für Werkstofftechnologie (LWT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407147480?language=en
• 关键词: Brazeability; similar; hybrid; joint; compounds

Selective-Laser-Melting (SLM) is a metal-powder-based manufacturing process that offers the best possible design options for the production of highly complex components. Until today, generating a SLM part on a simple geometrical, conventionally produced component requires such components to be segmented, brazed and tempered prior to realizing a hybrid joint compound. The disadvantages of this procedure are mainly based on the fact that the SLM part contains high residual stresses and has a completely different material structure in the generated state. Therefore, these compounds offer wholly dissimilar mechanical-technological properties. Furthermore, technically efficient SLM components require a subsequent heat treatment which extends the already complex production chain by another process step.Selective laser melting as well as a combined brazing/heat treatment processes offer a great potential to combine the respective advantages into an efficient production chain. As proven in preliminary tests, the residual porosity and oxide inclusions affect the brazing quality and the joint strength significantly, although the SLM materials had a density higher than 99.8 vol.-%. This research project will systematically generate fundamental knowledge to braze similar composite and hybrid composites of conventional and SLM material grades for austenitic stainless steel 316L (X2CrNiMo17-12-2) and nickel maraging tool steel 18Ni300 (X3NiCoMoTi18-9-5). Furthermore, the brazed joints will be benchmarked to appropriate composites which are only manufactured by selective laser melting. Additionally, the joints will be heat-treated to equalize the microstructure and minimize residual stresses. The overall objective is to establish a suitable process chain to produce similar hybrid composites of SLM and conventional materials, which is based on characteristic values of the mechanical joint properties. In detail, the focus of the research project is mainly the investigation of the brazing process using these material grades. The established brazing processes for conventional composites are transferred to these composites and analyzed with respect to the wetting and flow behavior, the joint strength, with a strong focus on the influence of pores and oxides within the SLM material to the brazing quality. In addition, gas phase etching followed by nickel plating of the joining surfaces will be examined for the brazing samples. These processes will remove the oxides and close the open porosity, thus enhancing the brazing quality and the joint strength significantly.

选择性激光熔化(SLM)是一种基于金属粉末的制造工艺，它为生产高度复杂的部件提供了可能的最佳设计选择。直到今天，在简单的几何形状、传统生产的部件上生成SLM零件需要对这些部件进行分段、焊接和回火，然后才能实现混合接头复合材料。这一过程的缺点主要是因为SLM零件包含高残余应力，并且在生成状态下具有完全不同的材料结构。因此，这些化合物提供了完全不同的机械技术性能。此外，技术上高效的SLM组件需要随后的热处理，这将本已复杂的生产链延长了另一个工艺步骤。选择性的激光熔化以及组合的铜焊/热处理工艺提供了将各自的优势结合到高效生产链中的巨大潜力。初步试验证明，尽管SLM材料的密度大于99.8vol.-%，但残余气孔率和氧化物夹杂物对焊接质量和接头强度有显著影响。该研究项目将系统地为316L奥氏体不锈钢(X2CrNiMo17-12-2)和镍马氏体工具钢18Ni300(X3NiCoMoTi18-9-5)焊接常规和SLM材料等级的类似复合材料和混杂复合材料提供基础知识。此外，钎焊接头将以适当的复合材料为基准，这些复合材料只能通过选择性激光熔化制造。此外，将对接头进行热处理，以使显微组织均匀，并将残余应力降至最低。总的目标是建立一条合适的工艺链，以机械连接性能的特征值为基础，生产出类似于SLM和常规材料的混杂复合材料。具体来说，研究项目的重点主要是研究使用这些材料牌号的钎焊过程。将已建立的传统复合材料的焊接工艺转移到这些复合材料上，并从润湿和流动行为、连接强度方面进行分析，重点关注SLM材料中的气孔和氧化物对焊接质量的影响。此外，还将对焊接样品进行气相腐蚀，然后对连接表面进行镀镍处理。这些工艺将去除氧化物并闭合开口的气孔，从而显著提高焊接质量和接头强度。