Aerospace materials are material

Material

Material is anything made of matter, constituted of one or more substances. Wood, cement, hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to...

s, frequently metal alloy

Alloy

An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

s, that have either been developed for, or have come to prominence through, their use for aerospace

Aerospace

Aerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space...

 purposes.

These uses often require exceptional performance, strength or heat resistance, even at the cost of considerable expense in their production or machining. Others are chosen for their long-term reliability in this safety-conscious field, particularly for their resistance to fatigue

Fatigue (material)

'In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.Fatigue occurs...

.

The field of materials engineering is an important one within aerospace engineering

Aerospace engineering

Aerospace engineering is the primary branch of engineering concerned with the design, construction and science of aircraft and spacecraft. It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering...

. Its practice is defined by the international standard

International standard

International standards are standards developed by international standards organizations. International standards are available for consideration and use, worldwide...

s bodies who maintain standards for the materials and processes involved. Engineers in this field may often have studied for degree

Academic degree

An academic degree is a position and title within a college or university that is usually awarded in recognition of the recipient having either satisfactorily completed a prescribed course of study or having conducted a scholarly endeavour deemed worthy of his or her admission to the degree...

s or post-graduate qualifications in it as a speciality.

History

Edwardian period
The first aerospace materials were those long-established and often naturally occurring materials used to construct the first aircraft. These included such mundane materials as timber

Timber

Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...

 for wing structures and fabric

Fabric

A fabric is a textile material, short for "textile fabric".Fabric may also refer to:*Fabric , the spatial and geometric configuration of elements within a rock*Fabric , a nightclub in London, England...

 and dope

Aircraft dope

thumb|right|[[United Kingdom military aircraft serials|2699]] a [[World War I]] [[Royal Aircraft Factory B.E.2]] finished in a clear dopeAircraft dope is a plasticised lacquer that is applied to fabric-covered aircraft...

 to cover them. Their quality was of utmost importance and so the timber would be of carefully selected sitka spruce

Sitka Spruce

Picea sitchensis, the Sitka Spruce, is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 95 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter...

 and the covering of irish linen

Irish linen

Irish linen is the brand name given to linen produced in Ireland. Linen is cloth woven from, or yarn spun from the flax fibre, which was grown in Ireland for many years before advanced agricultural methods and more suitable climate led to the concentration of quality flax cultivation in northern...

. Standards were required for the selection, manufacture, and use of these materials. These standards were developed informally by manufacturers or government groups such as HM Balloon Factory, later to become RAE Farnborough, often with the assistance of university engineering departments.

The next stage in the development of aerospace materials was to adopt newly-developed materials, such as Duralumin

Duralumin

Duralumin is the trade name of one of the earliest types of age-hardenable aluminium alloys. The main alloying constituents are copper, manganese, and magnesium. A commonly used modern equivalent of this alloy type is AA2024, which contains 4.4% copper, 1.5% magnesium, 0.6% manganese and 93.5%...

 the first age hardening aluminium alloy

Aluminium alloy

Aluminium alloys are alloys in which aluminium is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories...

. These offered attributes not previously available. Many of these new materials also required study to determine the extent of these new properties, their behaviour and how to make the best use of them. This work was often carried out through the new government-funded national laboratories, such as the Reichsanstalt (German Imperial Institute) or the British National Physical Laboratory (NPL).

World War I
The NPL was also responsible for perhaps the first deliberately-engineered aerospace material, Y alloy

Y alloy

Y alloy is a nickel-containing aluminium alloy. It was developed by the National Physical Laboratory during World War I, in attempt to find an aluminium alloy that would retain its strength at high temperatures....

. This first of the nickel-aluminium alloys was discovered after a series of experimentsExperiment 'Y' of the series, giving the alloy its name. during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, deliberately setting out to find a better material for the manufacture of piston

Piston

A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...

s for aircraft engine

Aircraft engine

An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...

s.

Interwar period
Between the wars

Interwar period

Interwar period can refer to any period between two wars. The Interbellum is understood to be the period between the end of the Great War or First World War and the beginning of the Second World War in Europe....

, many aerospace innovations were in the field of manufacturing processes, rather than just an inherently stronger material, although these too benefited from improved materials. One of the R.R. alloys, R.R.53B, had added silicon which improved its fluidity

Fluidity

Fluidity may refer toIn science*reciprocal of viscosity*Cognitive fluidity*Membrane fluidity*Sexual fluidityOthers*Fluidity *Dark Fluidity – a literature magazine*Empire Fane ship...

 when molten. This allowed its use for die casting

Die casting

Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process...

 as well as the previous sand casting

Sand casting

Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material.It is relatively cheap and sufficiently refractory even for steel foundry use. A suitable bonding agent is mixed or occurs with the sand...

, a means of making parts that were both far cheaper and also more accurate in shape and finish. Better control of their shape allowed designers to shape them more precisely to their tasks, leading to parts that were also thinner and lighter.

Many interwar developments were to aircraft engine

Aircraft engine

An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...

s, which benefited from the vast improvements being made for the growing car industry. Although not strictly an 'aerospace' innovation, the use of refractory

Refractory

A refractory material is one that retains its strength at high temperatures. ASTM C71 defines refractories as "non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above...

 alloys like Stellite

Stellite

Stellite alloy is a range of cobalt-chromium alloys designed for wear resistance. It may also contain tungsten or molybdenum and a small but important amount of carbon...

 and Brightray

Brightray

Brightray is a nickel-chromium alloy that is noted for its resistance to erosion by gas flow at high temperatures. It was used for hard-facing the exhaust valve heads and seats of petrol engines, particularly aircraft engines from the 1930s onwards...

 for the hard-facing of exhaust valves offered huge gains in the reliability of aircraft engines. This itself encouraged long-range commercial flights, as the new engines were reliable enough to be considered safe for long flights across oceans or mountain ranges.

World War II
The de Havilland Albatross

De Havilland Albatross

|-See also:...

 airliner of 1936 had a fuselage

Fuselage

The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

 of wooden sandwich construction: wafers of birch plywood

Plywood

Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

 were spaced apart by a balsa

Balsa

Ochroma pyramidale, commonly known as the balsa tree , is a species of flowering plant in the mallow family, Malvaceae. It is a large, fast-growing tree that can grow up to tall. It is the source of balsa wood, a very lightweight material with many uses...

 sheet. This same construction achieved fame with its wartime use in the Mosquito

De Havilland Mosquito

The de Havilland DH.98 Mosquito was a British multi-role combat aircraft that served during the Second World War and the postwar era. It was known affectionately as the "Mossie" to its crews and was also nicknamed "The Wooden Wonder"...

 fast bomber. As well as being a construction of light weight and high performance, it also avoided the use of aluminium, a strategic material during wartime, and could use the skills of woodworkers, rather than those of specialised aircraft metalworkers. When Germany attempted to copy this aircraft as the Moskito

Focke-Wulf Ta 154

|-See also:-External links:*...

it was a failure, primarily for materials reasons. The original specialist phenolic Tego film

Tego film

- Development and use for plywood :Tego film was developed in Germany around 1930 as a glue for waterproof plywood. It comprised a paper sheet pre-impregnated with a resole phenolic resin. When heated, assembled between wood veneers and then compressed, a strong and waterproof laminated plywood was...

adhesive was only produced by a factory that was destroyed by bombing. Its replacement led directly to catastrophic failures and loss of the aircraft.

Radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 became small enough to be carried on board aircraft, but the fragile feed horn

Feed horn

In satellite dish and antenna design, a feedhorn is a small horn antenna used to convey radio waves between the transmitter and/or receiver and the reflector, particularly in parabolic antennas...

s and reflector

Reflector (antenna)

An antenna reflector is a device that reflects electromagnetic waves.It is often a part of an antenna assembly.The most common reflector types are...

s needed to be protected and streamlined from the airstream. Moulded radome

Radome

A radome is a structural, weatherproof enclosure that protects a microwave or radar antenna. The radome is constructed of material that minimally attenuates the electromagnetic signal transmitted or received by the antenna. In other words, the radome is transparent to radar or radio waves...

s were constructed, using the Perspex acrylic plastic that was already in use for cockpit windows. This could be heated to soften it, then moulded or vacuum formed

Vacuum forming

Vacuum forming, commonly known as vacuuforming, is a simplified version of thermoforming, whereby a sheet of plastic is heated to a forming temperature, stretched onto or into a single-surface mold , and held against the mold by applying vacuum between the mold surface and the sheet.The vacuum...

 to shape. Other polymers developed at this time found uses in compact radio equipment as high-voltage insulators or dielectric

Dielectric

A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...

s.

Honeycomb structures were developed as flat sandwich sheets used for bulkheads and decking. These were long established with wood and paper board construction, but required a more robust material for aerospace use. This was achieved towards the end of the war, with all-aluminium honeycomb sandwiches.

Post-war

Marketing outside aerospace

The term "aerospace grade" has come to be a fashionable marketing slogan for luxury goods, particularly for cars and sporting goods. Bicycle

Bicycle

A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....

s, golf club

Golf club

A golf club is used to hit a golf ball in a game of golf. Each club is composed of a shaft with a grip and a clubhead. Woods are mainly used for long-distance fairway or tee shots; irons, the most versatile class, are used for a variety of shots; Hybrids that combine design elements of woods and...

s, sailing yacht

Yacht

A yacht is a recreational boat or ship. The term originated from the Dutch Jacht meaning "hunt". It was originally defined as a light fast sailing vessel used by the Dutch navy to pursue pirates and other transgressors around and into the shallow waters of the Low Countries...

s and even torch

Flashlight

A flashlight is a hand-held electric-powered light source. Usually the light source is a small incandescent lightbulb or light-emitting diode...

es are all sold on the basis of their high-performance materials, whether these are relevant or not. Since their appearance in 1979, Maglite

Maglite

Maglite is a brand of flashlight manufactured in the United States by Mag Instrument, Inc. located in Ontario, California, and founded by Anthony Maglica. It was introduced in 1979. Constructed principally of anodized 6061 aluminum, they have a variable-focus beam...

 have advertised their use of 6061 aluminium for their torch bodies, one of the first to make a deliberate feature of aerospace materials for a non-performance reason.

Some sporting uses have been for the material's actual qualities. Many ski makers have produced skis wholly from cloth and resin composite materials, using the tailorability of such construction to vary the stiffness, damping and torsional stiffness of a ski along its length. Hexcel

Hexcel

Hexcel is a materials company incorporated in Delaware and headquartered in Stamford, Connecticut that manufactures advanced composite materials and structural parts...

, a manufacturer of aluminium honeycomb sheet, became well-known for its branded skis, using this same advanced material.

Sporting uses may be every bit as demanding as aerospace needs. Particularly in cycling, materials may be loaded more highly than in aerospace use, the risk of failure being seen as more acceptable than for aircraft.

Many uses of aerospace materials for sporting goods have been as the result of a 'peace dividend

Peace dividend

The peace dividend is a political slogan popularized by US President George H.W. Bush and UK Prime Minister Margaret Thatcher in the early 1990s, purporting to describe the economic benefit of a decrease in defense spending. It is used primarily in discussions relating to the guns versus butter...

'. After World War II, Hiduminium

Hiduminium

The Hiduminium or R.R. alloys are a series of high-strength, high-temperature aluminium alloys, developed for aircraft use by Rolls-Royce before World War II. They were manufactured and later developed by High Duty Alloys Ltd....

 alloy appeared in bicycle brake components as its maker sought to expand new markets to replace their previous military aircraft. In the 1990s, both smelters and recyclers of titanium

Titanium

Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....

 sought new non-military markets after the end of the Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

, finding them in both bicycle frames and golf clubs.

Carbon fibre composite, and its distinctive weave pattern, has become a popular decorative choice on cars and motorbikes, even in purely decorative contexts such as dashboards. This has extended to the use of flexible stick-on patterned vinyl to reproduce the appearance, without any of the physical properties.