铣削MILLING

附录B  汉语翻译
铣削MILLING(中文2200字,英文1500字)
铣削是用铣刀进行多刃旋转加工的工艺。在这种工艺中，金属的切除是通过铣刀的旋转运动以及此同时工件的直线运动的组合来实现。铣削加工可用于生成平面、曲面和螺旋面，也用于螺纹和切齿加工。
当与工件金属啮合切入时，铣刀的每个刀刃相当于单刃刀片，因此，每个单刃片有一定的前角和后角，因为只有切削刃的一小部分与工件在同一时间接触，所以大切削量不会严重影响刀具的寿命。事实上，铣削加工的切削量与进给量比车和钻加工高出到4倍。并且铣削加工的工件表面质量通常高于那些被车，刨和钻的工件表面质量。
在工业上各种各样的铣刀得到了广泛的运用。这也与事实一致，铣削加工是个通用性极强的加工工具，也使得铣床成为工厂机加车间的生产主干。

附录A  英文原文
MILLING
Milling is a machining process that is carried out by means of a multiedge tool known as a milling cutter .In this process,metal removal is achieved through combining the rotary motion of the milling cutter and linear motions of the workpiece simultaneously.Milling operations are employed in producing flat ,contoured and helical surfaces as well as for thread-and gear-cutting operations.
Each of the cutting edges of a milling cutter acts as an individualsingle-point cutter when it engages with the workpiece metal .Therefore ,each of those cutting edges has appropriate rake and relief angles .Since only a few of the cutting edges are engaged with the workpiece at a time ,heavy cuts can be taken without adversely affecting the tool life .In fact ,the permissible cutting speeds and feeds for milling are there to four times higher than those for turning or drilling .Moreover,the quality of the surfaces machined by turning ,shaping ,or drilling.