Author: haroonkhan
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TEMPERATURE MEASUREMENT
Temperature of a body shows degree of hotness with respect to reference body. There are a number of temperature measurement systems, some of them are thermocouples, resistive temperature devices (RTDs and thermistors), infrared radiators, bimetallic devices, liquid expansion devices, change-of-state devices, etc.
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INTRODUCTION
In order to produce components, manufacturer have to know whether the components meet the required dimensional and accuracy standards. Companies carrying out maintenance activities also need to know that the components they are working with, repairing or servicing are to the required size and accuracy. Measurement plays an important role in establishing these needs and…
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Glasses
It is a super cooled amorphous material. It consists of more than 50% silica and other additives such as oxides of aluminium, sodium, calcium, magnesium, titanium, lithium, lead, and potassium. It has applications in windows, containers, lighting instruments, cookware, etc. The availability of various types of glasses is soda-lime glass, lead-alkali glass, borosilicate glass, etc.
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Silica
It is available in abundance in nature in the form of quartz. Most of the glasses contain more than 50% of silica. It is also used in electric materials to increase the magnetic permeability of the materials. It may be used in the form of silicates of various materials such as clay, asbestos, mica, glasses,…
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Ceramics
Ceramics are compound of metallic and non-metallic materials. It has properties of high compressive strength, low thermal expansion, high elasticity, high hardness, high wear resistance, and low electrical and thermal conductivity. Ceramics are used for tiles, pottery, and sanitary wares (porcelain). The raw materials used for ceramics are clay having fine sheet like structure, kaolin…
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Abrasive Materials
Abrasives are hard, non-metallic, sharp edged, and irregular shaped materials used to remove small amount of materials by cutting action. It may be used in bonded form or as free particles. It is employed in grinding, polishing, super finishing, buffing, and honing operations. Commonly used abrasives are alumina (Al2O3), silicon carbide (SiC), cubic boron nitride…
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Plastics
Common organic materials are plastics and synthetic rubbers which are termed as organic polymers. Other examples of organic materials are wood, many types of waxes and petroleum derivatives. Organic polymers are prepared by polymerization reactions, in which simple molecules are chemically combined into long chain molecules or three-dimensional structures. Organic polymers are solids composed of…
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Non-ferrous Metals
These substances are composed of metals other than iron. However, these may contain iron in small proportion. Six non-ferrous materials are available in sufficient quantity reasonably at low cost and used as common engineering metals. These are aluminium, tin, copper, nickel, zinc, and magnesium. Some other non-ferrous metals, about 14 in number, are produced in…
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Ferrous Metals
In ferrous materials the main alloying element is carbon (C). Depending on the amount of carbon present, alloys will have different properties, especially when the carbon content is either less/higher than 1.5%. This amount of carbon is specific as below this amount of carbon, material undergoes eutectoid transformation, while above that limit ferrous materials undergo…
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CLASSIFICATION OF ENGINEERING MATERIALS
Common engineering materials may be classified into one of the following seven groups: Metallic materials are broadly of two kinds—ferrous and non-ferrous materials. Ferrous materials are those in which iron (Fe) is the principal constituent. All other materials are categorized as non-ferrous materials.