Unconventional Applications of Electrical Discharge Machining

放电加工的非常规应用

• 批准号: RGPIN-2014-06529
• 负责人: Koshy, Philip
• 金额: $ 1.97万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=589069
• 关键词: Unconventional; Applications; Electrical; Discharge; Machining

Electrical discharge machining (EDM) is a precision material removal process that utilizes the heat generated from controlled, rapid electrical spark discharges struck between the tool and workpiece electrodes, in the presence of a dielectric fluid. Traditionally, the application domain of EDM has referred to the machining of difficult-to-cut materials, as the thermal mechanism of material removal is not limited by the hardness and toughness of the workpiece material, in contrast to cutting processes that entail plastic deformation. EDM has further been applied in the machining of geometric features such as internal cavities with sharp corners. The process is also used to machine thin/fragile workpieces, on account of the associated forces being relatively negligible due to there being no physical contact between the tool and the workpiece. As material removal in EDM entails localized melting and vaporization at the micro-scale, the generated surface comprises a large number of microscopic, overlapping craters. Accordingly, EDM is one of the very few manufacturing processes with the capability to generate surfaces with a positive skewness. This means that the surface comprises peaks interspersed among relatively wide valleys such that the height distribution is skewed to the right, which makes the surface ideally predisposed towards the novel applications that will be investigated in the proposed research. EDM further offers the flexibility to tailor the size and aspect ratio of the characteristic craters that collectively constitute the texture towards a specific application. This offers the exciting prospect of achieving even conflicting functional requirements, such as a reduction or enhancement of friction, in the same process by appropriately tuning the pulse parameters. In the context above, the objective of the proposed research is primarily to explore innovative, unconventional applications of EDM wherein material removal is not the primary intent per se, but rather a means to the end of engineering the topography of a surface towards realizing a specific functional attribute. In particular, the proposed work will refer to scientific investigations into: (1) the role of an EDM texture in providing nucleation sites for bubbles towards enhancing boiling heat transfer, with applications in the power generation and electronics industries, (2) texturing of automotive piston rings so as to enhance lubricant ingress and retention for reducing friction towards enhanced engine performance and fuel efficiency, (3) imparting an appropriate texture on metallic biomedical implants with a view to facilitating their integration into the bone structure, and (4) the use of EDM for the fabrication of water-repellent, self-cleaning surfaces with applications in the aerospace, marine and automotive industries. The research will further examine the application of EDM in texturing tooling surfaces in order to enhance adhesion between the substrate and a coating, explore the effect of an EDM texture on the drag against a moving fluid, and investigate the mechanism by which an EDM texture could be engineered to increase surface traction.

电气排放加工（EDM）是一种精确的材料去除过程，它利用在介电液存在下，在工具和工件电极之间施加的受控的快速电火花放电产生的热量。传统上，EDM的应用结构域是指难以切割材料的加工，因为材料去除的热机理不受工件材料的硬度和韧性的限制，而与切割需要塑性变形的过程相比。 EDM进一步应用于几何特征，例如具有锋利角的内部空腔。由于工具和工件之间没有物理接触，因此由于相关力相对可忽略的，该过程也用于加工薄/脆弱的工件。 由于EDM中的材料去除需要在微尺度上进行局部熔化和蒸发，因此生成的表面包括大量显微镜，重叠的陨石坑。因此，EDM是极少数具有正偏度表面的制造工艺之一。这意味着表面包括散布在相对较宽的山谷之间的峰，使高度分布向右偏斜，这使得表面理想地倾向于在拟议的研究中对新的应用进行研究。 EDM进一步提供了量身定制特征陨石坑的尺寸和纵横比，这些特征陨石坑集体构成特定应用的质地。通过适当调整脉冲参数，在同一过程中，在同一过程中实现了甚至相互冲突的功能要求，例如减少或增强摩擦。 在上面的上下文中，拟议的研究的目的主要是探索EDM的创新，非常规的应用，其中材料去除不是主要意图本身，而是一种工程结束的手段，以实现表面的地形，以实现特定的功能属性。 In particular, the proposed work will refer to scientific investigations into: (1) the role of an EDM texture in providing nucleation sites for bubbles towards enhancing boiling heat transfer, with applications in the power generation and electronics industries, (2) texturing of automotive piston rings so as to enhance lubricant ingress and retention for reducing friction towards enhanced engine performance and fuel efficiency, (3) imparting an appropriate texture on金属生物医学植入物，以促进其整合到骨骼结构中，（4）使用EDM用于制造水上，自我清洁的表面，并在航空航天，海洋和汽车工业中应用。这项研究将进一步研究EDM在纹理工具表面中的应用，以增强基板和涂层之间的粘附，探索EDM纹理对阻力对移动液的影响，并研究可以设计EDM纹理以增加表面牵引力的机制。