GOALI/Collaborative Research: Thermomechanical Investigations of High Speed Machining of Aluminum

GOALI/合作研究：铝高速加工的热机械研究

• 批准号: 0223611
• 负责人: John Dolbow
• 金额: $ 15.07万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0223611&HistoricalAwards=false
• 关键词: GOALI; Collaborative; Research; Thermomechanical; Investigations

During the machining of metals, plastic deformation and friction lead to the production of heat in the workpiece, which results in complex deformation in the cutting zone. Recently, several numerical models of this highly coupled process have been produced in response to the increased interest in high speed machining. However, while a small number of researchers, in the past and recently, have examined temperature fields during cutting at low or traditional cutting speeds, few if any experimental studies exist that measure temperature fields in the work piece during cutting at high speeds, i.e. 20-100 m/s. It is important to characterize the thermal field in the cutting zone during high speed machining in order to characterize friction and wear characteristics in this area and to understand the heat generated there, which affects chip formation and possibly residual stress formation as well. Ultimately, such investigations should direct further advancement in materials development for high speed machining applications. In this work, infrared detectors are used to experimentally measure the temperature distribution at the surface of a workpiece during high-speed orthogonal cutting, and complex numerical models are developed to predict and understand the active mechanisms of deformation and failure. Finally, from these temperature measurements and models, the heat generated in the primary deformation zone is examined, characterized and related to the residual stress distribution in the workpiece. The main thrust is to better understand, and therefore reduce, the effects of residual stress on distortion of high-speed machined, thin walled components. The approach draws on the experience of experimental, numerical and industrial researchers to attack this difficult, economically relevant problem with a comprehensive experimental, theoretical and developmental approach. Specific benefits of the proposed work are: (1) Detailed understanding the interplay between finished product quality, material behavior and heat generation in high speed machining; (2) New efficient and accurate computational algorithms to model high-speed machining in order to facilitate full understanding of the observed interactions between tool, material and cut quality or residual stress formation; and (3) New directions in aluminum alloy design for high-speed cutting with emphasis on minimizing the effects of machining and alloy processing parameters on the formation of residual stresses in the finished product. Overall, an integrated materials-mechanics/modeling-experimentation approach to the problem will be used throughout the work leading to a multidisciplinary solution to the problem of residual stress distortion of parts machined at high-speed.

在金属加工过程中，塑性变形和摩擦会导致工件中的热量产生，从而导致切割区的复杂变形。最近，由于对高速加工的兴趣增加而产生了这种高度耦合过程的几种数值模型。然而，尽管过去和最近的少数研究人员在低或传统的切割速度下进行了切割过程中检查了温度场，但很少有实验研究可以在高速切割时（即20-100 m/s）测量工件中的温度场。重要的是要在高速加工期间表征切割区的热场，以表征该区域中的摩擦和磨损特性并了解那里产生的热量，从而影响芯片形成以及可能的残留应力形成。最终，此类调查应指导高速加工应用材料开发的进一步进步。在这项工作中，红外探测器用于在高速正交切割过程中实验测量工件表面的温度分布，并开发了复杂的数值模型来预测和理解变形和失败的活动机制。最后，从这些温度测量和模型中，对主要变形区中产生的热量进行了检查，表征，并与工件中的残余应力分布有关。 主要的推力是更好地理解，因此减少残留应力对高速加工薄壁组件失真的影响。该方法借鉴了实验，数值和工业研究人员的经验，以全面的实验，理论和发展方法来攻击这个困难的，经济上相关的问题。拟议工作的具体好处是：（1）详细了解成品质量，材料行为和高速加工中热量产生之间的相互作用； （2）为高速加工建模的新高效，准确的计算算法，以促进对观察到的工具，材料和削减质量或残余应力形成之间观察到的相互作用的完全理解； （3）铝合金设计中的新方向，用于高速切割，重点是最大程度地减少加工和合金加工参数对成品中残留应力形成的影响。 总体而言，在整个工作中将使用一种集成的材料机械学/建模实验方法来解决该问题，从而为高速加工的零件的残留应力扭曲问题提供了多学科解决方案。