Ultrasonic Vibration Assisted Surface Texturing of Bulk Metallic Glasses for Enhancing Tribological Performance

超声波振动辅助块体金属玻璃的表面纹理以增强摩擦学性能

• 批准号: RGPIN-2018-04911
• 负责人: Jin, Xiaoliang
• 金额: $ 1.97万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712437
• 关键词: Ultrasonic; Vibration; Assisted; Surface; Texturing

My long-term research goal is to advance the understanding of the mechanics and the material response in precision manufacturing processes, in order to enhance the component surface quality including topography and microstructural property. In the next five years, my research will focus on the fundamental mechanisms in surface texturing of bulk metallic glasses (BMGs) with ultrasonic vibration assistance. BMGs are a new category of metal alloys with non-crystalline structure. BMGs have been increasingly used in various industrial applications, e.g. the bearing components. Surface texturing is a technique to generate repeated surface patterns which act as lubricant reservoirs to benefit the tribological performance of the bearing system. Existing surface texturing processes such as chemical etching and laser texturing are not suitable for BMGs because of their adverse environmental impact and process induced microstructure modification. Mechanical machining is able to achieve textured surface while keeping the original material phase. The main challenges of mechanical texturing are tool tip fracture and surface damages caused by the impact force. To overcome this barrier, a new texturing technique using high-feed milling with ultrasonic vibration assistance (VA) is proposed. VA modifies the tool tip trajectory and extensively reduces the chip load. It is hypothesized that the VA enhances the transition of BMG deformation from inhomogeneous to homogeneous mode, therefore reducing the surface damage. There is knowledge gap in understanding how the process parameters in surface texturing quantitatively influence the texture geometry and the surface quality. The following research plan is proposed: (1) a new micro-indentation technique with ultrasonic vibration feature will be developed to identify the constitutive behavior of BMG under large strain, high strain rate, varying temperature and repeated load; (2) the effect of texturing process parameters on the inhomogeneous-homogeneous deformations of BMG will be determined; (3) the surface topography as a result of the tool tip vibrations with 2D vibration assistance will be predicted. This proposed research is expected to bring broad impacts to industry. Biocompatible BMGs have been developed as new implant materials. The advantage of BMGs compared to conventionally used titanium is their low elastic moduli which nearly match that of bones, therefore reducing the damage to the bones. Surface texture is generated on the implant to enhance the bone-implant bonding. BMGs with surface texture also have been used as molds for the fabrication of structured micro optics. This research will provide guidance in determining process parameters to improve the texture quality without trial-and-error processes. As a result, a cost-effective surface texturing technique with high geometric accuracy and surface quality will be achieved.

我的长期研究目标是增进对精密制造过程中力学和材料响应的理解，以提高部件的表面质量，包括形貌和微观结构特性。在接下来的五年中，我的研究将集中于超声波振动辅助下大块金属玻璃（BMG）表面纹理化的基本机制。 BMG 是一类新型的非晶结构金属合金。 BMG 已越来越多地用于各种工业应用，例如：轴承部件。表面纹理是一种生成重复表面图案的技术，这些表面图案充当润滑剂储存库，有利于轴承系统的摩擦性能。现有的表面纹理化工艺（例如化学蚀刻和激光纹理化）由于其不利的环境影响和工艺引起的微观结构改变而不适用于 BMG。机械加工能够在保持原始材料相的同时获得纹理化的表面。机械纹理化的主要挑战是刀尖断裂和冲击力引起的表面损伤。为了克服这一障碍，提出了一种采用超声波振动辅助 (VA) 的高进给铣削的新纹理技术。 VA 修改了刀尖轨迹并大大减少了切屑负载。据推测，VA 增强了 BMG 变形从非均匀模式到均匀模式的转变，从而减少了表面损伤。在理解表面纹理中的工艺参数如何定量影响纹理几何形状和表面质量方面存在知识差距。 提出以下研究计划：（1）开发一种具有超声振动特征的新型微压痕技术，以识别BMG在大应变、高应变率、变温和重复载荷下的本构行为； (2) 确定毛化工艺参数对BMG非均匀-均匀变形的影响； (3) 将预测二维振动辅助下刀尖振动导致的表面形貌。 这项拟议的研究预计将为行业带来广泛的影响。生物相容性 BMG 已被开发为新型植入材料。与传统使用的钛合金相比，BMG 的优点是其弹性模量低，几乎与骨骼相匹配，因此减少了对骨骼的损伤。在种植体上生成表面纹理，以增强骨与种植体的结合。具有表面纹理的 BMG 也已被用作制造结构化微光学器件的模具。这项研究将为确定工艺参数提供指导，以提高纹理质量，而无需反复试验。因此，将实现具有高几何精度和表面质量的经济有效的表面纹理技术。