Formation of Super-hard Wear Resistant Coating using Energy Efficient Reactive Laser Additive Manufacturing Technique (REALM)

该领域项目将开发一种新的、可持续的制造技术，以生产井下钻井工具的硬面。这项专利技术采用一种基于定向能量沉积(DED)的新型金属添加剂制造工艺，使用元素粉末在原位形成高耐磨堆焊涂层。超硬涂层的特点是具有强大的冶金结合，显示出连续的金属基体和细小分散的碳化物析出物，创建了磨损和侵蚀应用所需的功能梯度组织。这克服了使用商用硬面碳化钨粉末时遇到的缺点。该项目预计将带来三项创新：1.自动化、低热量输入的制造工艺，以形成功能梯度的硬面；涂层-基材界面的高韧性和表面的高硬度。使用多种应用目标材料组合配制的活性粉末组合物。设计自由的硬面以优化涂层几何形状，以提高散热和性能。创新的DED工艺将有利于环境；近净成形工艺将导致更有效地应用钨和钴，从而将这些昂贵的高风险商品的浪费降至最低。使用激光束的局部加热将节省能源和温室气体。在使用中，井下工具将表现出更高的性能和更低的能源消耗，而其更高的寿命将减少对“危险”金属的初级生产的需求。

The REALM project will develop a new, sustainable manufacturing technology to produce hard-facings for downhole drilling tools. The proprietary technology uses a novel metal additive manufacturing process based on Directed Energy Deposition (DED) to form highly wear resistant hard-facing coatings in-situ, using elemental powders.The super-hard coating is characterised by a strong metallurgical bond showing a continuous metal-matrix and finely-dispersed carbide precipitates creating functional graded microstructure necessary for wear and erosion applications. This has overcome the drawback encountered when using commercial hard-facing tungsten carbide powders.The project is expected to deliver three innovations:1. Automated, low-heat input manufacturing process to form functionally-graded hard-facings; high toughness at the coating-substrate interface and high hardness on the surface.2. Reactive powder composition formulated using a wide variety of application-targeted material combinations.3. Design freedom of hard-facings to optimise coating geometries for improved heat dissipation and performance.The innovative DED process will benefit the environment; the near-net shape process will lead to more efficient application of tungsten and cobalt thus minimising waste of these expensive at-risk commodities. Localised heating using a laser beam will save energy and greenhouse gases. In service, the downhole tool will exhibit higher performance and will lower energy consumption, whilst its higher longevity will reduce the demand for the primary production of "at-risk" metals.