材料功能与信息专业英语复习

材料概论复习题

01·Thick sheets of flat glass is made by a special float process. 02·Excessive contents of MgO can lead to destructive(毁灭性的) expansion of hardened concrete.

03·As the carbon content of steel increases,steel becomes less ductile(柔软的),i.e.,more brittle.

04·Magnesium(镁) is hexagonal-close-packed(六方密堆积) in structure.

05·In the case of good glass forming materials like SiO2,GeO2 or B2O3, the required rate of cooling of the melts is remarkably low because the maximum crystallization velocities in these materials are themselves very low.

06·Dark color of Portland cement is caused by ferrite phase(铁素体),formation of which must be avoided in a white cement.

07· In a body-centred cell,there are two particles per elementary cell. 08·Fracture toughness(断裂韧性) is a generic term for measures of resistance to extension of a crack.

09·Anisotropy(各向异性) of properties is mainly observed in monocrystalline(单晶) solids.

10· Elastomers(橡胶) are the group of polymers that can easily undergo very

11· The favorable characteristic of graphite is best lubricity(润滑性). 12·Stiffness(刚度) is expressed by the modulus of elasticity(弹性),also called Young’s modulus.

13·When a liquid id=s cooled from a high temperature to its melting temperature,(Tm),it generally solidifies to a crystalline product.

14·There are four particles per elementary cell in a face-centred cell. 15·When carbon is mostly in the form of graphite spheroids(球状石墨) and is produced during solidification by inoculating(对金属溶液进行孕育处理) the cast iron with an element such as magnesium while it is still in the ladle(铸勺),the cast iron exhibits very ductile property.

16·Titanium is used in high-speed aircraft for its high strength at high temperatures.

17·Magnesium is the lightest of all structural metals.

18·There are four main aspects materials science and technology: synthesis, manufacturing and processing, composition and structure,properties and performance.

19·The silica structure is the basic structure for glass and ceramics. 20·Glasses are coloured with added oxides or halides(卤化物) and made to change their colours or become darker on exposure or light or heat. 21·Traditional fabrication techniques of ceramic contain Hydroplastic

22·The term bulk density is used in this instance to refer to a ceramic’s porosity and the fact that most ceramics contain both a crystalline and a noncrystalline phase.

翻译

1·Glass when newly formed, with a perfect surface, is very strong about five times as strong as steel. This may seem strange, but theoretically glass should be very strong because of the nature of its interatomic bonds. In practice the strength is very much less than the theoretical value. One of the main causes of this loss of strength is the presence of surface defects, such as those caused by chemical corrosion or mechanical abrasion. These flaws can be very small but because glass is rigid they act to concentrate any applied stress over only a few interatomic bonds at the apex of the crack. Under these conditions the strong bonds break and fracture occurs.

玻璃刚成型时有着完美的表面，强度是钢的5倍，这看起来或许很奇怪，但由于本身原子间价键的性质，玻璃理论强度应该很大，实际强度却比理论强度低很多。强度损失的主要原因之一是表面缺陷的存在，例如那些化学腐蚀和机械磨损所造成的缺陷。这些裂纹可能很小，但因为玻璃是刚性的，所以缺陷会集中所有外加作用力于少数裂纹尖端的原子键上。在这些条件下，强价键断裂伴随破裂产生。