材料成型及控制工程专业英语11.casting

1、材料成型及控制工程专业英语Translation Skill Semantic Extension （翻译技巧 句子成分转换）谓语、表语、宾语、状语转译成主语；主语、定语、表语、状语转译成谓语；主语、状语、宾语转译成定语；定语、谓语、主语转译成状语；主语、状语、谓语转译成宾语；主语、宾语转译成表语。 句子成分转换是指词类不变而成分改变的译法。通过改变原文中某些句子成分，以达到译文逻辑正确、通顺流畅、重点突出等目的。谓语、表语、宾语、状语转译成主语Gases differ from liquids in that the former have greater compressibility t

2、han the latter.译：气体和固体的区别，在于前者比后者有更大的压缩性。（谓语转译成主语）Rubber is a better dielectric but a poorer insulator than air.译：橡胶的介电性比空气好，但绝缘性比空气差。（表语转译成主语）Water has a density of 62.4 pounds per cubic foot.译：水的密度是每立方英尺62.4磅。（宾语转译成主语） Aluminum is very light in weight, being only one third as heavy as iron.译：铝的重量很

3、轻，只有铁的1/3.（状语转译成主语） The same signs and symbols of mathematics are used throughout the world.译：全世界都使用同样的数学记号和符号。（状语转译成主语）谓语、表语、宾语、状语转译成主语主语、定语、表语、状语转译成谓语The prevention of many types of occupational diseases isdistinctly within the realm of possibility.译：许多职业病显然可以预防。（主语转译成谓语）A semiconductor has a poor

4、 conductivity at room temperature, but it may become a good conductor at high temperature.译：在室温下，半导体导电率差，但在高温下，它可能成为良导体。（定语转译成谓语） The wide applications of computers affect tremendously the development of science and technology.译：计算机的广泛应用，对科学技术的影响极大。（状语转译成谓语）Also present in solids are numbers of free

5、 electrons.译：固体中也存在着大量的自由电子。（表语转译成谓语）主语、定语、表语、状语转译成谓语主语、状语、宾语转译成定语CMOS chips in the computer work a thousand times more rapidly than nerve cells in the human brain.译：电脑芯片的工作比人类大脑中的神经细胞要快1000倍。（主语转译成定语） In Britain the first stand-by gas-turbine electricity generator was in operation in Manchester in

6、1952.译：英国的第一台辅助燃气发电机于1952年在曼彻斯特开始运转。（状语转译成定语） By 1914 Einstein had gained world fame.译：1914年爱因斯坦已成了著名的科学家。（宾语转译成定语）定语、谓语、主语转译成状语After more experiments, Galileo succeeded in making a much better telescope.译：又做了一些实验之后，伽利略成功地制造了一架好得多的望远镜。（谓语转译成状语） The result of its revolutionary design is that the engi

7、ne is much smaller, works more smoothly, and has fewer moving parts.译：由于他在设计上的革新，发动机变得小多了，工作得更平稳了，活动部件也少了。（主语转译成状语）It was an amazing piece of scientific clairvoyance, comparable perhaps to Charles Babbages anticipation of the principle of the computer.译：这个理论在科学上充满了元件卓识，也许可以跟巴贝奇的计算机原理相提并论。（定语转译成状语）定语

8、、谓语、主语转译成状语主语、状语、谓语转译成宾语The mechanical energy can be changed back into electrical energy by means of a generator.译：利用发电机可以把机械能重新转变成电能。（主语转译成宾语）Television has been successfully sent by laser, too.译：用激光发射电视也获得了成功。（状语转译成宾语） The sun affects tremendously both the mind and body of a man. 译：太阳对人的身体和精神都有极大的

9、影响。（谓语转译成宾语）主语、宾语转译成表语A great contribution of Edison was the carbon microphone.译：炭精传声器是爱迪生的一大贡献。（主语转译成表语） The production had considerable difficulty getting patent protection if it had no patent right.译：如果产品没有专利权，要获得专利保护是相当困难的。（宾语转译成表语） 由此看来，句子成分的转译显得变化万千，异彩纷呈，难于穷究，几乎所有的句子成分都可以互相转译。进行成分转译的目的是为了使译文通顺

10、，合乎汉语习惯和更好地跟上下文响应。CHAPTER 11 CASTING11.1Various Casting Processsand mold 砂型plastic-bonded shell mold 塑性粘结壳型die-casting metal mold 压铸用金属型plaster mold 石膏型investment 熔模铸造shrinkage 收缩flask 砂箱core 型芯dry sand molds 干砂铸型- 12 -CHAPTER 11 CASTING11.1Various Casting Processgreen sand mold 湿砂铸型thermosetting re

11、sin 热固树胶（脂）centrifugal casting 离心铸造low-melting alloys 低熔点合金silica 硅石，硅土，无水硅酸ethyl silicate 硅酸乙酯tilting furnace 可倾式铁炉- 13 -砂型和芯是用型砂和芯砂制造的。型(芯)砂是由原砂、粘结剂、水和附加物按一定比例混合制成。用一种遇热硬化的型砂（酚醛树脂覆膜砂）覆盖在加热到180280的金属模板上，使其硬化为薄壳（薄壳厚度一般为612毫米），再加温固化薄壳，使达到足够的强度和刚度，因此将上下两片型壳用夹具卡紧或用树脂粘牢后，不用砂箱即可构成铸型，浇注铸件金属模板的加热温度一般为300左右

12、，使用的型砂为树脂砂，即以酚醛树脂为粘结剂的树脂砂。同样也可用上述方法将型芯制成薄壳芯制造薄壳铸型常用翻斗法。制造薄壳芯常用吹制法。- 17 -CHAPTER 11 CASTING The principal casting processes are classified according to the kind of mold used. These are sand molds, plastic-bonded shell molds, permanent and semipermanent metal molds, die-casting metal molds, plaster mo

13、lds, and investment molds.主要的铸造工艺是根据使用的模具种类来分类的。模具类型是砂型，塑性粘结壳型，永久和半永久性的金属型，压铸金属模型，石膏模具，熔模铸型。 classify 分类；分等permanent 永久的砂型铸造视频- 18 -CHAPTER 11 CASTING The first step in the production of a sand casting is to make a metal or wooden pattern.The pattern is a replica of the part being made but has sligh

14、tly larger dimensions to allow for shrinkage during solidification and cooling of the casting. 砂型铸造生产的第一步是制造一副金属或木质模型。该模型是所铸零件的复制品，但是考虑到铸件凝固和冷却过程中产生收缩，这个模型尺寸有些许放大。 replica 复制品，复制物shrinkage 收缩- 19 -CHAPTER 11 CASTINGThe pattern is often made in two or more parts so it can be removed easily from the m

15、old. To make the mold, sand is rammed or packed around the pattern, the sand being held in place by a boxlike container known as a flask. 木模往往被做成两部分或更多部分，所以他们能够很容易地从模具中（这个模具其实就是沙子制成的）取出。为做出这个模具，砂子在木模周围要压紧、夯实，砂子被放在称为铸型砂箱的盒子形状的容器内。ram 压实、夯实 packed 充满的，塞满了的boxlike 箱型的 flask 砂箱、铸型砂箱 - 20 -CHAPTER 11 CAS

16、TINGAfter the flask is filled with sand, the pattern is withdrawn, leaving a mold cavity similar to the finished casting.当砂箱充满砂子后，木模被抽回，剩下具有与成型铸件一模一样的模具型腔。 withdraw 取出；撤退- 21 -CHAPTER 11 CASTINGIf there are hollow spaces in the casting, such as an axle hole in a wheel, sand molded to the shape of th

17、e hollow space must be placed in the mold cavity. These void-producing shapes are known as cores. 如果铸件有中空部分，例如轮零件的中间轴孔，在这种模具型腔中，需要放置被制成中空形状的型砂。那些能形成中空形状的型砂被称为型芯。hollow 中空的、空心的 axle hole 轴孔 void-producing 产生空隙 core 型芯- 22 -CHAPTER 11 CASTINGThe sand used for the mold and cores is held together by cla

18、y and cereal-bonding agents. If the molds are baked, they are known as dry sand molds. If used in the moist condition, they are known as green sand molds. 用于模型和型芯的砂子是用粘土和谷物粘结剂粘结在一起的。如果模型进行烘干，他们就被称作干砂铸造。如果在潮湿的条件下使用，他们就被称作湿砂铸造。clay 粘土、白土、泥土 cereal-bonding agents谷物类粘结剂 baked 烤 moist 潮湿- 23 -CHAPTER 11

19、CASTINGDry sand molds are stronger than green sand molds and show greater resistance to erosion and crushing. Surface quality of sand castings is improved by covering the pattern with a fine sand known as facing sand before ramming the balance of the sand.干砂模型比湿砂模型要坚固，而且表现出较强的耐侵蚀和抗压碎能力。在对砂子进行均匀紧实之前，

20、通过对砂型表面覆盖被称为面砂的细砂，能使砂型铸件的表面质量得到了提高。crushing 压碎、破碎- 24 -CHAPTER 11 CASTINGPlastic-bonded shell molding is a modification of sand casting. A metal pattern is heated to about 350F( 175 C ) and then clamped on top of a box containing a mixture of fine sand and a thermosetting resin.塑性粘结壳型铸造是砂型铸造的改良。先把金属

21、模型加热到175度，然后固定在装满细砂和热固树脂的盒子的顶部。 clamp 夹紧、夹持、卡紧 thermosetting resin 热固塑胶（脂）壳型铸造视频- 25 -CHAPTER 11 CASTING When the box is inverted and its contents fall on the hot pattern, the resin is softened by heat. This causes a thin shell of molding material to form around the pattern. 当盒子倒置过来时，盒子里的砂子会落在热的模型上，

22、树脂就会被热软化。这样就在模型周围形成了一个薄薄的模具的壳。invert 倒置- 26 -CHAPTER 11 CASTINGThe box is then returned to its original position, and the unreacted resin and sand fall away from the pattern. After the resin has had time to harden fully the shell is stripped. 然后盒子返回原位，没有起作用的树脂和砂子就会落下离开模型。当树脂经过一定的时间重复硬化后，这层壳就被剥离。unre

23、acted 没有起反应、没有起作用resin 树脂- 27 -CHAPTER 11 CASTINGA finished mold consists of two matching shells held firmly together and surrounded by metal shot (or some other backing material) that is kept in place by a flask. Use of metal shot increases the speed of cooling and solidification.一副完成的模具包含两个紧紧地固定在一

24、起的匹配的壳，并环绕着模具包裹着的铁丸（或者一些其他的基底材料），运用金属喷丸会提高冷却和固化的时间。- 28 -CHAPTER 11 CASTINGPermanent and semipermanent molds are made of metal. Permanent molds use metal cores if coring is required. Semipermanent molds use sand cores. The halves of the mold are frequently hinged and fastened with a screw device. 永久

25、或半永久型模具由金属制成。如果需要型芯永，那么久性模具使用金属芯。半永久性模具运用的是砂芯。两半模具频繁地被铰链在一起并被螺旋装置固定。hinged 铰链、用铰链（结合、附着）fastened 扣紧、固定、关牢 screw 螺旋（丝、孔、钉）- 29 -CHAPTER 11 CASTINGMold coatings or washes consisting of a refractory material, a lubricant such as graphite or rouge, and a binder, are used to assist removal of the casting

26、 from the mold. Different mold materials are used depending upon the metal being cast. 模具涂料或薄涂浆中包含有耐火材料，石墨或过氧化铁粉的润滑剂，粘结剂，涂料用来帮助从模具中取出铸件。模具材料的运用依赖于铸造的金属不同。washes 涂浆、洗涤剂 refractory 耐火的lubricant 润滑剂；润滑油 graphite 石墨rouge 红铁粉，三氧化二铁 binder 粘结剂- 30 -CHAPTER 11 CASTINGCentrifugal casting is a special form o

27、f permanent mold casting, using a rotating mold that throws the metal outward against the mold walls. It is used for castings that have a rotational axis of symmetry, such as pipe, gun tubes, and gear stock.离心铸造是永久性模具铸造的特殊形式，它运用旋转的模具把金属向外正对着抛向模具四壁。常用于具有对称性旋转轴的铸件，像管状铸件、炮管、齿轮装置。centrifugal casting 离心铸

28、造 gear stock 齿轮装置离心铸造视频- 31 -CHAPTER 11 CASTINGDie casting is an improved version of permanent mold casting. The essential features of a die-casting die are shown in Fig. 11.1. In die casting, the molten metal is forced into the mold or die under pressure. 压铸是永久型金属模铸造的改进的形式。图11.1表示了压铸模的基本特征。在压铸模铸造中，

29、熔融的金属在压力的作用下进入型腔。version 版本- 32 -CHAPTER 11 CASTINGHalf of the die is rigidly attached to the frame of the die-casting machine, and the other half is movable. Design of the die is such that the casting tends to adhere to the movable portion of the die.一半模具被刚性地固定在压铸机的框架上，另一半模具能够运动的。模具如此设计，能使铸件依附于模具的动

30、模部分。rigidly 刚性地 frame 框架；结构adhere 依附；粘着 portion 部分- 33 -CHAPTER 11 CASTINGAs the mold opens, the casting is carried with the movable portion of the die until knocked clear by the ejector pins shown in Fig. 11.1. Dies are oil-or-water-cooled to permit more-rapid operation. 随着模具的打开，铸件跟随动模部分运动直到由推杆把铸件完

31、全推离模具，如图11.1。为了快速生产，模具用水路或者油路冷却。knock 敲；打 clear 完全地ejector pins 顶杆 ；推杆- 34 -CHAPTER 11 CASTINGWhen hot metal enters the mold, it forces the air from the die cavity through shallow grooves ground in the die faces. Some die-casting machines are also fitted with vacuum devices that evacuate the die cav

32、ity before the hot metal is charged into it. 当热的金属液进入模具，金属液就会把模具型腔内的气体通过分型面的浅槽排出去。一些压铸机也安装有装置，能在热的金属液充填型腔之前就抽空模具型腔中的气体。 shallow 浅的、薄的 groove 槽、沟 vacuum 真空 evacuate 抽空、排空 charged into 冲向- 35 -CHAPTER 11 CASTINGThis reduces the amount of air trapped in the casting and produces more dense metal and mor

33、e sound casting.这样就减少了铸件中的含气量，生产出更致密更光洁的金属铸件。 trapped in 把关在里dense 稠密的；浓厚的 sound 好的- 36 -CHAPTER 11 CASTINGPlaster molds are similar to sand molds, except that a mixture of plaster of Paris and water is poured into a flask that holds a pattern. After the plaster begins to set, the pattern is withdra

34、wn.石膏型模具铸造与砂型铸造像类似，除了熟石膏和水的混合物是浇注进装有模型型腔的砂箱。当石膏模制成之后，模型被撤走。plaster of Paris 熟石膏石膏型铸造视频1石膏型铸造视频2- 37 -CHAPTER 11 CASTINGIf cores are required, they too are made of plaster. Molds and cores are baked to eliminate water and produce a porous mold through which entrapped air and gases can escape.如果需要型芯，它

35、们也被做成石膏型芯。烘烤模具和型芯排除水分，并生产出透气的模具，通过它能够使空气或其他气体排出。eliminate 排除 entrapped 诱捕, 使陷入圈套 porous 1. 多孔的 2. 渗水的;透气的- 38 -CHAPTER 11 CASTINGInvestment molds are used for making precision castings. This casting technique is also known by the name lost wax process. The process is unique in that both a new patter

36、n and a new mold are required for each casting. 熔模铸造用来制造精磨铸件。这种铸造技术也被叫做“失蜡铸造”这个名字。每制造一个铸件，都需要新模型和新模具，只有熔模铸造有这一特点。wax 蜡 permanent 永久的熔模铸造视频- 39 -CHAPTER 11 CASTINGThermoplastic or thermosetting resins, low-melting alloys, mercury, and waxes have been used to make patterns. The pattern is, in reality,

37、 a die-casting or injection-molded plastic or wax part reproducing the details of the finished object. 热塑性或热固性树脂，低熔点合金，水银和石蜡已经被用来做制作模型。事实上，模型是一个压铸件或注射模制作的塑料件或蜡件，这些塑件或蜡件能翻印出成品件的细节。 mercury 汞、水银 reproducing 仿制、模拟、翻印finished object 成品、光制品- 40 -CHAPTER 11 CASTINGThe pattern is dipped into a mixture of w

38、ater and fine-grained refractory of creamy consistency. This forms a thin layer corresponding to facing sand on the surface of the pattern. 把模型浸入水和细粒耐火材料组成的油状混合物。这样模型表面的面砂就产生一层薄层的壳。dip 把浸入 fine-grained 细粒的 creamy 含乳油的consistency 稠度，稠性corresponding to 相对于、对应于- 41 -CHAPTER 11 CASTING Coarse-grained si

39、lica is then sifted over the pattern and some of the particles are retained by the wet refractory coating. The coarse particles act as an anchor for the backing material of the mold. 大晶粒的硅土从模型上被淘汰下来，一些微粒通过液态耐火涂料被保留。那些大粒硅土可以当作模具基体材料固定器。coarse-grained 粗粒的 sifted 过滤、挑选、淘汰 particles 微粒、小粒 anchor 锚、固定器-

40、42 -CHAPTER 11 CASTINGThe pattern is next placed in a flask that is filled with a substance such as silica flour bonded with ethyl silicate. The backing material sets, and the flask and contents are fired at high temperature to melt or burn out the pattern and drive off all moisture. 接下来，模型被放置在砂箱中，砂

41、箱中充满着诸如被硅酸乙脂粘结在一起的硅砂粉这样的材料。基体材料装置和砂箱及其内容物在高温下开始熔化或烧尽，从而除去掉所有的水分。silica flour 硅砂粉 silicate 硅酸乙脂moisture 水分- 43 -CHAPTER 11 CASTINGA clean mold cavity remains, which has the same shape as the original pattern. Casting is often accomplished by clamping the mold on top of a tilting furnace.这样一个光滑的型腔就被保留

42、下来，它与原始模型有着相同的形状。铸件经常通过被固定在倾转炉的顶部的模具来完成。tilting furnace 倾转炉CHAPTER 11 CASTING11.2Properties of Castingwrought form 精炼状态ductility 延展性 toughness 韧性 void 缩孔 impurity content 杂志含量 gas bubble 气泡 residual strength 残余应力 creep strength 抗蠕变强度 equiaxed grain 等轴晶 - 44 -CHAPTER 11 CASTING11.2Properties of Casti

43、ngequicohesive temperature 等内聚性温度fluidity 流动性amorphous glassy structure 无定形玻璃态组织 metglass 金属玻璃，非晶态金属supersaturation 过饱和ferromagnetic 铁磁的，铁磁体hysteresis 磁滞现象eddy 旋转，漩涡 - 45 - 46 -CHAPTER 11 CASTINGDepending upon the particular casting process and the alloy used, the properties of castings vary greatly

44、. Mechanical properties are probably of greatest importance.由于铸造工艺和使用合金的不同，铸件的性能差别很大。其中，力学性能是很重要的。tilting furnace 倾转炉- 47 -CHAPTER 11 CASTINGGenerally speaking, cast metal has inferior properties when compared to the same metal in wrought form. This is particularly true with respect to ductility and

45、 toughness at room temperature. However, proper design may cancel out these inherent shortcomings. 一般而言，相同的材料，相较于锻造金属而言，铸造金属具有较差的性能。尤其是在室温下的延展性和韧性方面，更是如此。然而，正确的设计可能会抵消这些固有的缺点。inferior 差的，下级的 wrought 锻造的 inherent 固有的with respect to 关于 ductility 延展性 toughness 韧性- 48 -CHAPTER 11 CASTINGThe lack of duct

46、ility probably arises from the void spaces that tend to be present in cast metal. The voids originate partly through evolution and entrapment of gases as the metal solidifies. In the case of die castings, there is the added problem of air trapped in the die.缺乏延展性可能由于铸造金属中往往存在缩孔造成的。缩孔的产生，部分是由于金属凝固过程中

47、的气体析出和滞留造成的。在压铸过程中，还会有排气不良造成的问题。arises from 由引起，起因于 originate 发源；发生evolution 变化，演进 entrapment 截留- 49 -CHAPTER 11 CASTINGMelting under a vacuum and casting into an evacuated mold increase the soundness of cast metal and lower the impurity content. These techniques result in better fabricating and ser

48、vice properties and are applied to production of high-quality alloy steels and other critical alloys. 在真空下融化并浇注进真空模具中，能提高铸造金属的稳定性，降低杂质含量。这些技术带来更好的加工特性及使用性能，并适用于生产高品质合金钢及其他重要合金。soundness 稳定性fabricating 制备，制作- 50 -CHAPTER 11 CASTINGVoids also originate as a result of contraction of the metal as it sol

49、idifies. Voids of this type are both microscopic and macroscopic in nature and, because of their sharp angular form, are worse stress raisers than the rounded voids produced by gas bubbles.金属的凝固收缩也会导致缩孔。这种类型的缩孔在形式上既有微观的也有宏观的，且由于它们在形状上存在尖锐的棱角，所以比气泡所引起的圆形缩孔更容易产生应力集中。contraction 收缩，紧缩 microscopic 微观的ma

50、croscopic 宏观的 stress raisers 局部应力集中- 51 -CHAPTER 11 CASTINGShrinkage tendencies continue as the metal cools in the solid state and uneven rates of cooling produced by the geometry of the casting set up shrinkage stresses that may cause cooling cracks. Proper design and inspection should eliminate th

51、is type of structural defect.随着固态金属的冷却，金属继续收缩。由于铸件的几何形状，会导致冷却速率不均匀，这会导致产生收缩应力，并可能导致冷却裂纹。适当的设计和检验应消除这种类型的结构缺陷。contraction 收缩，紧缩 microscopic 微观的macroscopic 宏观的 stress raisers 局部应力集中- 52 -CHAPTER 11 CASTINGStresses remaining in the casting may be insufficient to cause immediate fracture. However, upon

52、application of a small external load, fracture occurs. Residual stresses of this type can and should be eliminated by annealing the casting.铸件中残余的应力可能不足以导致立即断裂。然而，再加载一个小的外部载荷，就会发生断裂。这种类型的残余应力可以并且应该通过退火来消除。external 外部的annealing 退火- 53 -CHAPTER 11 CASTING Ductility is also affected by the grain shape

53、and grain orientation of the casting. Solidification shrinkage voids and low-melting, embrittling impurities tend to concentrate at the grain boundaries, causing planes of brittleness and weakness to develop in some castings as shown in Fig. 1l.2.延展性也受铸件的晶粒形状和晶粒取向影响。凝固缩孔和低熔点脆性杂质倾向于集中于晶界，从而在某些铸件形成脆性和

54、低强度的平面，如图1l.2所示 。embrittling 脆化的- 54 -CHAPTER 11 CASTING Yield strength, creep strength, and ductility tend to be affected by cooling and solidification rates. Castings cooled very quickly, as in die and permanent mold castings, have fine, equiaxed grains.屈服强度，蠕变强度和延展性往往受到受冷却和凝固速率的影响。在锻压模具和永久铸模中，铸件冷

55、却速度非常快，会形成细小的等轴晶。equiaxed 等轴的，各向等大的- 55 -CHAPTER 11 CASTING In precision castings, the cooling rate is sometimes intentionally kept low so that the grains are coarse and equiaxed.在精密铸造中，有时特意保持较低的冷却速度，以获得粗大的等轴晶。intentionally 特意地，有意地- 56 -CHAPTER 11 CASTINGThe effect of grain size on yield strength ha

56、s been discussed earlier. Finer grain sizes not only improve strength, but also improve ductility. In regard to creep strength, fine grain sizes seem more desirable only for resisting deformation below the equicohesive temperature.前面已经讨论过晶粒大小对屈服强度的影响。细小的晶粒不仅提高强度，还提高延展性。至于蠕变强度，细晶粒只是在低于等强温度时才能较好地抵御变形。

57、equicohesive 等强度的- 57 -CHAPTER 11 CASTINGAbove the equicohesive temperature coarse grain sizes improve strength. Thus, for high-temperature service at relatively low stresses and strain rates, precision-cast, slow-cooled, coarse-grained components are frequently desired. 在等强温度以上，粗大晶粒提高强度。因此，在高温，相对较低

58、的应力和应变速率下服役的机件，通常需要精密铸造，缓慢冷却，粗晶粒度。- 58 -CHAPTER 11 CASTINGThe very best high-temperature performance is achieved by controlling the solidification of precision-cast turbine buckets. In this application, single-crystal blades are formed having the orientation that best resists stress at high temperat

59、ure.最优良的高温性能是通过控制精密铸造涡轮叶片凝固来实现。在此应用中，形成的单晶叶片具有方向性，次方向是高温下最能抵抗应力的方向。turbine buckets 涡轮机叶片single-crystal 单晶- 59 -CHAPTER 11 CASTINGSurface smoothness is dependent upon the particular casting process. Sand castings have the poorest surface finish of all castings. Castings made in plastic-bonded shell-m

60、olds and plaster mold castings have somewhat better surface smoothness.表面光滑度是依赖于特定的铸造工艺。砂型铸件是所有铸件中表面光洁度最差的。在塑性粘结壳模具和石膏模的铸件具有较好的表面光洁度。plastic-bonded shell-molds 塑性粘结壳模具plaster mold 石膏模- 60 -CHAPTER 11 CASTINGMetal mold castings, if made in well-finished dies in good condition, have a very good surfac