华南理工大学机械工程专业英语翻译

Unit 1

Metal generally have good electrical and thermal conductivity and good mechanical properties, such as high strength, high stiffness, and good ductility.

A ceramic an inorganic nonmetallic material with high stiffness and high brittleness.

The difference between glass production and ceramic production is that glass production could be manufactured by casting and blowing, while production of ceramics could only be made by sintering and firing.

Composites, always with high modulus, are formed from two or more types of materials and properties of composites are superior to any individual component.

Fracture toughness can be defined as a material's ability to avoid fracture when a flaw is introduced.

Fiber-reinforced composites are used in some of the advanced expensive sports equipment, such as a time-trial racing bicycle frame which consists of carbon fibers in a thermoset polymer matrix.

Polymers are used widely because they are lightweight, corrosion resistant, easy to process at low temperatures, and generally inexpensive. It’s mechanical properties are high strength and high stiffness.

Unit 2

The portions of the iron-carbon diagram near the ferrite region and those above 2% carbon content are deleted.

Metallurgy is the physics, chemistry, and engineering related subject, which focus on metals from ore extraction to the final product.

Heat treatment can remove internal stresses, reduce grain size, increase toughness, and produce a hard surface on a ductile interior.

Temperature and the rate of cooling are the two main controlling factors in heat treatment.

Steels having less than the eutectoid amount of carbon (less than 0.77%) are known as hypoeutectoid steels.

Hardening is the process of heating a piece of steel to a temperature within or above its critical range and then cooling it rapidly.

The primary purpose of annealing is to soften hard steel so that it may be machined or cold worked.

Unit 4

Forging is the process by which metal is heated and is shaped by plastic deformation by suitably applying compressive force.

With proper design, the grain flow can be oriented in the direction of principal stresses encountered in actual use.

One valuable feature of forging is that it improves the strength of the metal by refining the grain structure and making it uniform.

Forgings are consistent from piece to piece, with any of the porosity, voids, inclusions and other defects.

Open die forgings or hand forgings are made with repeated blow in an open die, where the operator manipulates the workpiece in the die.

In roll forging, a round bar stock is placed between die rollers which increases the length axially.