基于矩形网格高速铣削的加工路径优化

基于高速铣削的加工特点,对矩形网格加工路径进行优化,对优化后的不同轨迹受力情况进行仿真分析。通过实物切削验证,记录各种加工路径的主轴振动情况。结果表明:采用螺旋式加工路径切削过程最稳定,最适合高速铣削加工。

直纹面叶轮变轴插铣半精加工刀位算法

针对三轴叶轮流道粗铣法加工余量不均的问题,提出了基于曲面法向刀具半径偏置法的流道变轴插铣半精加工的刀心点和刀轴矢量计算方法,采用现有的刀心点和安全高度的迭代算法确定了刀具插削和抬刀的轴向位置,所得刀位可有效去除三轴流道开粗法给叶片各部留下的不均匀余量。经对直线轴联动高速端铣和定轴插铣粗加工后的流道进行变轴插铣半精加工的切削实验验证,刀位算法正确,可给后续精加工留下均匀余量,后续叶片精加工可顺利进行。

Chip Formation in Micro-cutting

The miniaturisation context leads to the rise of micro-machining processes. Micro-milling is one of the most flexible and fast of them. Although it is based on the same principles as macro-cutting, it is not a simple scaling-down of it. This down-sizing involves new phenomena in the chip formation, such as the minimum chip thickness below which no chip is formed. This paper presents a review of the current state of the art in this field from an experimental and a numerical point of view. A 2D finite element model is then developed to study the influence of the depth of cut on the chip formation. After the model validation in macro-cutting, it highlights the phenomena reported in literature and allows to perform a minimum chip thickness estimation.

高速钢刀具激光熔覆WC/Co涂层工艺研究及性能验证

针对高速钢刀具在高速切削、高硬材料切削时硬度及红硬性不足的问题,采用激光熔覆技术在M2高速钢车刀上制备WC/Co熔覆层以改善刀具性能。研究了不同预加工形貌对熔覆层的影响,对熔覆过程中车刀刃倾角角度差异性问题提出了解决方法,并对熔覆后刀具进行了实际切削性能验证。结果表明,预置坡口熔覆为相对理想的预加工形貌,所得熔覆层的显微硬度较车刀基体提高了近57%,600℃时熔覆层红硬性提高了0.25倍,且熔覆层在1 000℃时红硬性达到了50 HRC以上,设计专用熔覆翻转夹具可以有效的调整刀具刃倾角角度。熔覆后车刀在高硬材料和高速切削中展现出优良的实用性能。