材料科学与工程专业英语(第四版)--第四章第3节翻译

4.3 Precision Casting

Metal casting has a historic pedigree as the manufacturing process first used by man to produce intricate metal articles and art objects.It played a major role in the industrial revolution and remains the basis of current manufacturing equipment and manufactured goods.The process plays an important part in aerospace component production and,as such ,remains at the leading edge of technology development.Despite the competition from plastics and ceramics,metal still remain the dominant materials in the production of capital equipment and manufactured goods.Metal casting will continue to play a major role,as a manufacturing process of considerable versatility,for the foreseeable future

金属铸造被人类作为生产工艺首次使用在复杂的金属制品和艺术品上有悠久的历史。它在工业革命中发挥了重大作用，仍然是当今设备和产品制造的基本方法。这种工艺在航空零部件生产中起着重要的作用，因此，仍然是科技发展的前沿技术。尽管有塑料和陶瓷的竞争，金属仍然作为主要材料来生产重要设备和产品。在可预见的未来，金属铸造作为一种被广泛考虑的制造工艺方法将继续发挥重要作用。

In common with other other manufacturing processes,metal casting has not remained static and there have been significant developments in both the metallurgy of cast alloys and in casting processes.It is the developments in processing,and particularly those devised to improve precision,which is the focus of this pass age.The objectives of these introductory passages are to establish the context wthin which precision casting processes are operated.This requires a definition and description of metal casting,a consideration of the attributes of metal casting in relation to other manufacturing processes,a summary of the structure of the foundry,and a definition of the term precision in the context of metal casting

与其他制造工艺相比，金属铸造不是静止不变的，在冶炼铸造合金和铸造工艺上有了重大发展。铸造工艺的发展，尤其是为提高铸造精度的设计，是过去铸造工艺的重点。这些介绍性段落是为了建立精密铸造工艺实施的背景。这就需要一个定义来描述金属铸造，与其他制造工艺相比，金属铸造有自己的特征，需要概述铸造工业的结构和定义精密金属铸造。

4.3.1 Metal Casting

In the metal casting process a metal,or more commonly an alloy,is heated until it is molten,whereupon it is poured into a mold or die that contains a cavity which represents the shape of the component or casting to be produced.In the case of a mold the cavity is produced by a pattern which is a replica of the component required,whereas in the case of a die the cavity replicating the shape of the component is produced by machining.Molds are invariably expendable,being destroyed when the casting is removed.Dies,on the other hand,are permanent and may be used to produce a succession of casting.Patterns may also be permanent or expendable.A permanent pattern is reusable,whereas an expendable pattern is consumed during the process of mold or casting production

在金属铸造过程中，一种纯金属（或更普遍的是一种合金）加热到熔化，然后浇入能呈现零件形状的铸模或金属模型腔中。一般铸模的型腔是通过能复制零件形状的模样来生产的，而金属模一般是通过机加工来制造具有零件外形的型腔。铸型都是一次性的，当铸件取出时铸型都会被破坏。另一方面，金属型是永久性的，可用于连续生产铸造。模样也可以是永久性的或一次性的。永久性模样是可以重复使用的，而一次性模样在铸造生产中消失。

4.3.2 Sand Casting

In the traditional sand casing process,sand is mixed with clay and water to produce a moldable mixture.The moistened clay provides the bonding agent which binds the sand grains together