谁有关于机械设计的英语论文啊，2000字左右，带翻译就更完美了，谢谢大家帮帮小弟，急需

Introduction
Machining aims to generate the shape of work-piece form a solid body,or to improve the tolerances and surface finish of a previously formed work-piece,by removing excess materials in the form of chips. Machining is capable of creating geometric configurations,tolerances, and surface finishes often unobtainable by any other technique.However, machining removes materials, which has already been paid for, in the form of relatively small particles that are more difficult to recycle and are in greater danger of becoming mixed. Therefore,developments often aim at reducing or-if at all possible-eliminating machining, especially in mass production.For these reasons, machining has lost some important markets, yet, at the same time, it has also been developing and especially having captured new markets with the application of numerical control.
Some feel for the important of machining may be gained from the observation that in 1983 there were about 2 million metal-cutting machine tools in the unite states ( of which some 5% were numerically controlled ) and that labor and overhead costs amounted to $125 billion, or 3% of the GNP.机加工的目的是给工件造形或改善去掉多余的材料后的公差或表面的精度。机加工能够达到几何形状，公差及表面精度，这些通常其他的技术都达不到。然而，机加工去掉的材料，却是之前已经付费购买的，加工后成为很小的屑状很难再利用并且混在一起很危险。所以，经常开发以减少或尽最可能去消除机加工，特别是在大规模加工中。鉴于这些原因，机加工已经失去了一些重要的市场，但是，同时，它也获得了进一步的发展，特别是在数控应用下又获得了一些新的市场。
对机加工重要性的了解可以从1983年的一些数字中得到，在美国有大约两百万的金属加工工具（其中5%为数控）和达1250亿或3%的GNP的人工成本。