Modeling of High Speed Machining of Difficult-to-Machine Materials

这笔赠款提供资金用于开发不同工作材料的高速加工(HSM)的分析模型和实验验证。具体地说，将使用不同的难加工材料，如钛合金、镍基高温合金和淬火钢，使用经典的Jeager的固定和移动热源模型，考虑各种热源(初级、预热和镜像)，对HSM中的剪切局部化进行热模拟。根据不同材料的热-机械剪切不稳定性来预测剪切局部化的发生。根据被加工材料的热机械性能和切割条件，将确定剪切失稳开始时的切割速度。除了精密车床和数控铣床等传统机床外，还将使用高速主轴(Bryant)(50,000转/分，50马力)进行高速加工测试。将尝试使用先进的热敏涂料和光学红外技术来测量在剪切局部条件下加工产生的温度。一些难加工的材料，包括钛合金、镍基高温合金和硬化钢，在航空航天和飞机工业中是具有挑战性的材料。正在专门开发新的刀具材料和刀具几何形状，以显著提高机械加工的生产率。对切屑形成过程、力、能量消耗、刀具磨损等方面的基本知识可以为该技术在工业上的实施提供基础。PI将与工具制造商以及飞机和汽车行业就这一技术进行互动。基础设施的发展和合格研究生和本科生(包括在美国出生的女性和少数族裔)的培训可以为推动美国工业的制造技术提供必要的人力资源。

This grant provides funding for the development of an analytical model and experimental verification of high-speed machining (HSM) of different workmaterials. In specific, thermal modeling of shear localization in HSM will be conducted using different difficult-to-machine materials, such as titanium alloys, nickel-based superalloys, and hardened steels taking into account various heat sources (primary, preheating, and image) using the classical Jeager's stationary and moving heat source models. The onset of shear localization will be predicted based on thermo-mechanical shear instability of different workmaterials. Depending on the thermo-mechanical properties of the workmaterial and the cutting conditions, the cutting speed for the onset of shear instability will be determined. In addition to the conventional machine tools, such as a precision lathe and an NC milling machine, a high-speed spindle (Bryant) (50,000 rpm, 50 hp) will be used for conducting the high-speed machining tests. Attempts will be made to measure the temperature generated in machining under shear localized conditions using either advanced thermally sensitive paints and optical infrared techniques.Some of the difficult-to-machine materials including titanium alloys, nickel-base superalloys, and hardened steels are challenging materials in the aerospace and aircraft industries. New tool materials and tool geometries are being specifically developed to dramatically increase the productivity in machining. Fundamental knowledge on the nature of chip formation process, forces, energy consumed, tool wear can provide the basis for the implementation of this technology in industry. The PIs would interact with tool manufacturers as well as aircraft and automobile industries on this technology Development of infrastructure and training of qualified graduate and undergraduate students (including the U.S. - born , women, and minorities) can provide the human resources necessary for advancing manufactuirng technologies in the U.S. industry.