Non ferrous alloy

Alloy are prepared in order to improvise mechanical and physical properties, a decrease in weight, increase in strength, attractive color, etc.

Summary

Alloy are prepared in order to improvise mechanical and physical properties, a decrease in weight, increase in strength, attractive color, etc.

Things to Remember

Aluminum alloys are easily formable and they can be worked upon by rolling, extruding, drawing, machining and other mechanical processes.
Magnesium alloys are mixtures of magnesium with other alloying elements, often Al, zinc, manganese, Si, Cu, rare earth metals and zirconium.
Copper based alloys benefit by strengthening mechanisms as they improve the mechanical properties of copper alloys.
Brass is an alloy made of copper and zinc; the composition of Zn and Cu can be varied to create a range of brasses with varying properties.
Bronze is principally an alloy of Cu and Sn . Bronze does not necessarily contain tin, and a variety of alloys of copper, including alloys with arsenic K, Al, Mn, and Si, are commonly termed "bronze".
Titanium alloys are the mixture of titanium and other chemical elements. Titanium alloys have good tensile strength and toughness (even at elevated temperatures).

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Subjective Questions

Q1:

Write a short note on Anti- Septics and Disinfectants.

Type: Short Difficulty: Easy

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Answer: <h4>Antiseptics and Disinfectants</h4>
Phenol
Phenolic disinfectants have been used as low and intermediate-level disinfectants. Phenolic disinfectants are effective bactericides, fungicides, tuberculocidal and virucides, but are ineffective against spore-forming bacteria such as Clostridium difficile. Phenolic disinfectants disrupt the cell membrane of microorganisms, and two phenol derivatives used commonly in hospital disinfectants are orthophenylphenol (Amphyl, Reckitt Benckiser) and ortho-benzyl-para chlorophenol (Clorox Disinfectant Cleaner, The Clorox Company).
Formaldehyde
It is primarily available as a water-based solution called formalin, which contains 37% formaldehyde by weight - is used as a high-level disinfectant and sterilant. Formaldehyde exerts its bactericidal, tuberculocidal, fungicidal, virucidal and sporicidal effects in the aqueous state, as well as in combination with low-temperature steam.
This extremely reactive chemical's mechanism of action is attributed to it's interactive and cross-linking properties of protein, DNA, and RNA in vitro, resulting in the disruption of DNA synthesis. It can also penetrate bacterial spores.
Formaldehyde has been traditionally used to sterilise equipment such as surgical instruments and haemodialysers in combination with alcohols. Paraformaldehyde, a solid polymer of formaldehyde, is used in combination with low-temperature steam for the disinfection of heat-sensitive medical equipment.
Hydrogen peroxide
Disinfectant solutions containing 7.5% hydrogen peroxide have been approved by the US FDA for sterilisation and high-level disinfection in health care settings.
It's good, broad-spectrum bactericidal, virucidal, sporicidal and fungicidal properties, combined with its excellent stability and environmentally friendly characteristics, have made hydrogen peroxide the disinfectant of choice for semi-critical and non-critical equipment while being an ideal surface disinfectant.
Despite not being listed as equipment-compatible by all endoscope manufacturers, hydrogen peroxide-based disinfectant solutions are still considered ideal alternatives for other toxic sterilants, such as ethylene oxide and aldehyde disinfectants. Hydrogen peroxide produces destructive hydroxyl-free radicals that act on membrane lipids, DNA, and other essential cell components.
FDA-cleared hydrogen peroxide-based disinfectants include Sporox Sterilizing & Disinfection Solution (Sultan Chemists) and Resert XL HLD High-Level Disinfectant (STERIS).
Dettol
Dettol is an antiseptic. It is a mixture of chloroxylenol and terpineol in a suitable solvent. Chloroxylenol has both antiseptic and disinfectant properties.
Iodine
Iodine is powerful antiseptic. It is used as a tincture of iodine which is 2-3% iodine solution of alcohol-water.
Cresol
Cresols (also hydroxytoluene) are organic compounds which are methyl phenol. They are a widely occurring natural and manufactured group of aromatic organic compounds, which are categorized as phenols (sometimes called phenolics). Depending on the temperature, cresols can be solid or liquid because they have melting points not far from room temperature. Like other types of phenols, they are slowly oxidized by long exposure to air and the impurities often give cresols a yellowish to brownish red tint. Cresols have an odor characteristic to that of other simple phenols, reminiscent to some of a "coal tar" smell. The name cresol reflects their structure, being phenols, and their traditional source, creosote.
Cresols are precursors or synthetic intermediates to other compounds and materials, including plastics, pesticides, pharmaceuticals, and dyes.
Dettol
The original Dettol liquid antiseptic and disinfectant is light yellow in colour in the concentrated form but, as several of the ingredients are insoluble in water, it produces a milky emulsion of oil droplets when diluted with water, exhibiting the ouzo effect.
The active ingredient in Dettol that confers its antiseptic property is chloroxylenol (C8H9ClO), an aromatic chemical compound. Chloroxylenol comprises 4.8% of Dettol's total admixture with the rest made up by pine oil, isopropanol, castor oil, soap, and water.
Diluted, Dettol may be used to clean cuts, wounds, etc. and to disinfect environmental surfaces such as household floors and the walls of slaughterhouses etc.
Potassium permanganate
Potassium permanganate is an inorganic chemical compound with the chemical formula KMnO4. It is a salt consisting of K+ and MnO−4 ions. Formerly known as permanganate of potash or Condy's crystals, it is a strong oxidizing agent. It dissolves in water to give intensely pink or purple solutions, the evaporation of which leaves prismatic purplish-black glistening crystals. In 2000, worldwide production was estimated at 30,000 tonnes. In this compound, manganese is in the +7 oxidation state.
An oxidant, potassium permanganate can act as an antiseptic. For example, dilute solutions are used to treat canker sores (ulcers), disinfectant for the hands and treatment for mild pompholyx, dermatitis and fungal infections of the hands or feet.
Povidone iodine
Povidone-iodine (PVP-I), brand name Wokadine, Pyodine, and Betadine is a stable chemical complex of polyvinylpyrrolidone (povidone, PVP) and elemental iodine. It contains from 9.0% to 12.0% available iodine, calculated on a dry basis.
This unique complex was discovered in 1955 at the Industrial Toxicology Laboratories in Philadelphia by H. A. Shelanski and M. V. Shelanski. They carried out tests in vitro to demonstrate anti-bacterial activity and found that the complex was less toxic in mice than tincture of iodine.
Povidone-iodine is a broad-spectrum antiseptic for topical application in the treatment and prevention of infection in wounds. It may be used in first aid for minor cuts, grazes, burns, abrasions, and blisters.
Chloride
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as a hydrogen chloride is dissolved in water or other polar solvents. Chloride salts such as sodium chloride are often very soluble in water. It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating fluid in and out of cells. The word chloride can also form part of the name of chemical compounds in which one or more chlorine atoms are covalently bonded. For example, methyl chloride, more commonly called chloromethane, (CH3Cl) is an organic compound with a covalent C−Cl bond. It is not a source of chloride ion.
Chlorhexidine
Chlorhexidine is an antibacterial used as an antiseptic and for other applications. It is a cationic poly biguanide (bisbiguanide). It is used primarily as its salts (e.g., the dihydrochloride, diacetate, and digluconate).
Chlorhexidine is an antibacterial used as an antiseptic and for other applications. It is a cationic poly biguanide (bisbiguanide). It is used primarily as its salts (e.g., the dihydrochloride, diacetate, and digluconate).
Cetrimide
Cetrimide is an antiseptic which is a mixture of different quaternary ammonium salts including Cetrimonium bromide (CTAB). It was first discovered and developed by ICI and introduced under the brand name Cetavlon. It is used as a 1-3 % solution for cleaning roadside accident wounds. Another antiseptic Chlorhexidine was also discovered and first developed by ICI. ICI also introduced Savlon which was a combination of Cetrimide and Chlorhexidine. ICI later sold the Savlon brand OTC to Johnson & Johnson in May 1992.
Ethanol
Ethanol also commonly called alcohol, ethyl alcohol, and drinking alcohol, is the principal type of alcohol found in alcoholic beverages, produced by the fermentation of sugars by yeasts. It is a neurotoxic, psychoactive drug, and one of the oldest recreational drugs. It can cause alcohol intoxication when consumed in sufficient quantity.
Ethanol is used in medical wipes and in most common antibacterial hand sanitizer gels at a concentration of about 62% v/v as an antiseptic. Ethanol kills organisms by denaturing their proteins and dissolving their lipids and is effective against most bacteria and fungi, and many viruses. Ethanol is ineffective against bacterial spores.
Gentian violet
Gentian violet belongs to the group of medicines called antifungals. Topical gentian violet is used to treat some types of fungus infections inside the mouth (thrush) and of the skin. Gentian violet is available without a prescription.
Gentian violet belongs to the group of medicines called antifungals. Topical gentian violet is used to treat some types of fungus infections inside the mouth (thrush) and of the skin.
Using a cotton swab, apply enough gentian violet to cover only the affected area. If you are applying gentian violet to affected areas in the mouth, avoid swallowing any of the medicine. If you are using gentian violet in a child's mouth, make sure you understand exactly how to apply it so that it is not swallowed. If you have any questions about this, check with your health care professional. Do not apply an occlusive dressing (airtight covering, such as kitchen plastic wrap) over gentian violet. It may cause irritation of the skin.

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ANTISEPTICS AND DISINFECTANTS

Non ferrous alloy

Aluminium Alloys

They are the alloys where aluminium (Al) is the predominant metal. The elements mixed are Cu, Mn, Mn, Si, and Zn. There are two principal classifications, namely 1.casting alloys and 2. wrought alloys, both of these classifications are further subclassified into the 2 types i.e. heat-treatable and non-heat-treatable.

Properties

1.They are easily formable and they can be worked upon by rolling, extruding, drawing, machining and other mechanical processes.

2. They have high thermal and electrical conductivity and do not show ductile to brittle transition at low temperatures.

3.Cast aluminium alloys have low melting point, although they generally have lower tensile strengths than wrought alloys.

4.The tensile strength of pure aluminum is around 90 Mpa but this can be increased to over 690 Mpa for some heat-treatable aluminum alloys.

Uses

Non-heat treatable aluminum alloys are used for making

electrical components,
heat preserving foil,
food packaging,
beverage can bodies,
architectural uses,
filler metal welding,
while heat treatable aluminum alloys are used for truck wheels, aircraft skins, pistons, canoes, railroad cars and aircraft frames.
Advanced aluminum alloys have enabled the design of high-speed ships, by lightening hulls by 40% to 50% over steel.
Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required.

Magnesium Alloys

Magnesium alloys are mixtures of magnesium with other alloying elements, often Al, zinc, manganese, Si, Cu, rare earth metals and zirconium. Magnesium alloys have a hexagonal lattice , this property which affects the fundamental properties of such alloys.

Properties

1.Magnesium is the lightest structural metal and its alloys containing Lithium have extremely light weight.

2. Magnesium has a low modulus of elasticity and very low resistance to fatigue, creep,wear, and tear.

3.Magnesium alloys can be strengthened either by dispersion strengthening or age hardening.

4.Magnesium alloys with fewer impurities and high Cerium content form a protective layer of MgO making it corrosion resistant.

5.Magnesium alloys are easily machined, cast, forged, and welded.

Uses

1.Magnesium alloys are used for aerospace applications, high-speed machinery, and materials handling equipment.

2.Casted magnesium alloys are used for many components of modern light cars, and Mg block engines have been used in some high-performance vehicles.

3.Magnox (alloy), whose name is for 'magnesium non-oxidising', is 99% Mg and 1% Al, and used in the cladding of fuel rods in some nuclear power stations.

4. They are now also used in jet-engine parts, rockets, and high range missiles, frames in luggage , portable power tools, and cameras and optical instruments.

5. They are also used in pyrotechnics, especially in incendiary bombs, as a fuse for thermite.

Copper Alloys

Copper alloys have higher densities than that of steels. Copper based alloys benefit by strengthening mechanisms as they improve the mechanical properties of copper alloys. Copper containing 0.1% impurities is used for electrical and microelectronics applications. Small amounts of cadmium, silver, and Aluminium oxide improve their hardness without impairing conductivity. Cold working is used for strengthening of single phase copper based alloys.

Properties

1.They are better resistant to creep, fatigue, and wear.

2. Most of the high ductility, corrosion resistance, electrical and thermal conductivity and can be joined and fabricated into complex shapes easily.

3. The face centred cubic structure of copper provides excellent ductility and high strain hardening coefficient.

4.Copper alloy corrodes easily by reacting with sulphur and forms a green layer on the surface.

Uses

1.Copper-based alloys are used in pumps, valves and plumbing parts where their properties are used as advantages.

2. Copper-based alloys are used as decorative items because of the changing colours as it reacts with different elements.

3. Copper and its alloys are widely used in making wires for electrical transmission since they have excellent electrical and thermal performance, good resistance to corrosion, and relatively low cost.

4. Integrated circuits and printed circuit boards use copper and its alloys in place of aluminum because of its superior electrical conductivity.

Types of Copper alloys

a.Brass

Brass is an alloy made of copper and zinc; the composition of Zn and Cu can be varied to create a range of brasses with varying properties. Brass is a substitutional copper alloy.The relatively low melting point of brass (900 to 940 °C, depending on composition)

Uses:

It is used for decoration for its bright gold-like appearance; for applications where less friction drive is required such as locks, gears, bearings, doorknobs, ammunition casings and valves; for plumbing and electrical applications;
extensively in brass musical instruments such as horns and bells for its acoustic properties.
It is also used in zippers.
Brass is often used in situations where it is important that sparks not be struck, as in fittings and tools around explosive gases

b.Bronze

Bronze is principally an alloy of Cu and Sn . Bronze does not necessarily contain tin, and a variety of alloys of copper, including alloys with arsenic K, Al, Mn, and Si, are commonly termed "bronze". It is generally harder than wrought iron however metal fatigue is more than steel and is a better thermal and electrical conductor than most steels.

Uses:

Bronze was especially preferred for use in boat and ship fittings prior to the extensive employment of stainless steel owing to its combination of toughness and corrosion resistance to salt water corrosion. Bronze is still today commonly used in ship propellers and water submerged bearings. It is used to make bronze sculpture. Many bronze alloys have the unusual and very desirable characteristics of expanding slightly just before they set, thus provide the highest filling in the finest details of a mold. Bronze parts are kind of tough and specifically used for bearings, electrical connectors, clips, and springs.

Nickel and Cobalt Alloys

Nickel and Cobalt have high strengths and high melting points and thus are used for corrosion protection and high-temperature resistance. Solidified powders of nickel and cobalt based superalloys can be formed by using spray atomization followed by hot isostatic pressing which is then used for making rings that retain the turbine blades. Since Iron, Nickel and Cobalt are magnetic, they form very good magnetic materials.

A Ni-Fe alloy Invar displays approximately no expansion during heating and is hence used in producing bimetallic composite materials. Cobalt is used for absorbing shocks and vibrations in cutting tools.

Titanium Alloys

Titanium alloys are the mixture of titanium and other chemical elements. Titanium alloys have good tensile strength and toughness (even at elevated temperatures). They are unusually light in weight, have unexpected corrosion resistance and the higher ability to withstand extremely high temperatures. Unfortunately, the high cost of both raw materials making up alloy limit their use to military applications, aircraft, spacecraft, medical devices, connecting rods Nickel and Cobalt are used on expensive sports cars and some premium sports equipment and consumer electronics. Auto manufacturers Porsché and Ferrari also use titanium alloys in engine components due to its durable properties in these high-stress engine environments.

Excellent corrosion resistance makes titanium suitable for chemical processing equipment, marine usable components, and biomedical implants. Titanium alloys are also used in making airframes and jet engine components.

Refractory Metals

Refractory metals are metals with really high melting points normally above 2000°C. This category consists of tungsten, molybdenum, tantalum and niobium. These metals are therefore used for their high-temperature services such as filaments in light bulbs, rocket nozzles, nuclear power generators, tantalum and niobium based capacitors and chemical processing equipment. However, their high densities limit their specific strengths.

Refractory metals rapidly oxidize between 200 and 425°C and are therefore contaminated or embrittled. Hence, special precautions are required during casting, welding, hot working or powder metallurgy. For tungsten filaments, preserving in vacuum protects it from oxidization. As refractory metals have B.C.C crystal structure, they have low ductile to the brittle transition temperature. Further alloying of refractory metals produces improved mechanical properties along with improving high-temperature properties.

Lesson

Non-Ferrous Alloys

Subject

Mechanical Engineering

Grade

Engineering

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