Advanced diagnostics and controls of thermal spray coating processes

热喷涂是最常用的涂层技术之一，在航空航天、汽车、生物医学、能源等工业领域有着广泛的应用。热喷涂技术用途广泛，金属、陶瓷、聚合物及其复合材料可被喷涂以制备高性能涂层/薄膜。沉积过程包括在基材上喷涂熔融或半熔融的颗粒(液滴)，这些颗粒(液滴)变平、固化和积累，形成呈现非常典型的片层结构的涂层。研究喷涂参数与飞行中颗粒特性以及飞行中颗粒特性与实际涂层性能之间的关系(流程图)为更好地控制喷涂过程和高效设计高性能涂层提供了必要的数据。拟议的计划旨在开发诊断和建模工具，使我们能够根据对喷涂过程中发生的复杂转变/转移过程的更基本的了解来定制涂层属性。悬浮式热喷涂(STS)这一新兴技术将成为人们关注的焦点。这一过程可以通过将纳米或亚微米粉末悬浮在液体载体(通常是乙醇或水)中来进行喷雾。这使得可以沉积具有独特微观结构的涂层，这些涂层比常规热喷涂工艺中通常产生的涂层精细一到两个数量级。这些纳米结构带来了沉积涂层的新的和改进的性能，这在要求苛刻的应用中得到了寻求。新兴的STS工艺有可能取代更昂贵的PVD/CVD工艺，因为它不需要昂贵的真空系统，并允许在大型部件上沉积。然而，为了实现这一愿景，有必要更好地了解和控制涂层结构和性能。这一研究小组的研究成果将有助于全面了解热喷涂过程，尤其是新出现的STS过程。这一新知识将通过培训HQP以及在加拿大的关键工业部门开发和部署先进的涂层和传感技术，即航空航天、能源和自然资源，刺激加拿大热喷涂市场的增长。经过培训的HQP将获得先进制造方面的经验和技术专业知识，这是对加拿大经济至关重要的工业部门。开发的诊断技术和模型至关重要，因为它们将被广泛用于在更多应用研究主题中开发创新的STS应用程序，我们希望在我们新成立的热喷涂和表面工程加拿大研究教席中解决这些问题。事实上，我们将广泛使用这些工具来优化和控制新兴STS应用中的涂层特性，如热障涂层、燃料电池、传感器、功能涂层、活性薄膜等。

Thermal spray is one of the most used coating technologies with applications in several industrial sectors such as aerospace, automotive, biomedical, energy, etc. The technology is versatile as metals, ceramics, polymers and their composites can be sprayed to produce high-performance coatings/films. The deposition processes involve spraying on a substrate molten or semi-molten particles (droplets) that flatten, solidify and accumulate forming a coating presenting a very typical lamellar structure. The study of the relationships (process maps) between the spray parameters and in-flight particle characteristics and between in-flight particle characteristics and actual coating properties brings the data necessary to better control the spray processes and design efficiently high performance coatings. The proposed program targets the development of diagnostic and modeling tools that will permit us to tailor coating properties based on a more fundamental understanding of the complex transformation/transfer processes occurring during spraying. An important focus will be given to the emerging technology of suspension thermal spray (STS). This process enables spraying nano- or submicron powders by suspending them in a liquid carrier (commonly ethanol or water). This allows the deposition of coatings with unique microstructures that are one to two orders of magnitude finer than those normally generated in conventional thermal spray processes. These nano-scale structures bring new and improved properties of the deposited coatings that are sought in demanding applications. The emerging STS process has the potential of replacing much more expensive PVD/CVD processes as it does not require expensive vacuum systems and allows deposition on large components. To achieve this vision although, it is necessary to better understand and control coating structure and properties. The research outcomes of this DG will contribute to develop a comprehensive understanding of thermal spray processes and, more particularly, of the emerging STS process. This new knowledge will stimulate the growth of thermal spray markets in Canada by training HQP and by developing and deploying advanced coating and sensing technologies in key industrial sectors for Canada; that is to say; aerospace, energy and natural resources. The trained HQP will gain experience and technical expertise in advanced manufacturing, an industrial sector of fundamental importance to the Canadian economy. The developed diagnostic techniques and models are crucial as they will be extensively used for developing innovative STS applications in the more applied research themes we want to address in our newly establish Canada Research Chair in Thermal Spray and Surface Engineering. Indeed, we will use extensively these tools to optimize and control coating characteristics in emerging STS applications such as thermal barrier coatings, fuel cells, sensors, functional coatings, active membranes, etc.