Hiduminium
Encyclopedia
The Hiduminium or R.R. alloys are a series of high-strength, high-temperature aluminium alloy
s, developed for aircraft use by Rolls-Royce
before World War II
. They were manufactured and later developed by High Duty Alloys Ltd.. The name Hi-Du-Minium is derived from that of High Duty Alloys.
The first of these Hiduminium alloys was termed 'R.R.50' . This alloy was first developed for motor-racing piston
s, and was only later adopted for aircraft engine use. It was a development of the earlier Y alloy
, the first of the nickel
-containing light aluminium alloy
s. These alloys are one of the three main groups of high-strength aluminium alloys, the nickel-aluminium alloys having the advantage of retaining strength at high temperatures, making them particularly useful for pistons.
engine that was successful in the Schneider Trophy
seaplane races. They quickly spread to other manufacturers, in 1931 being adopted by ABC
for their Hornet
engine. R.R.50 alloy was used for the crankcase, R.R.53 for the pistons.
Their first mass production use was in the Armstrong Siddeley Special
saloon car of 1933. Armstrong Siddeley already having had experience of the alloy, and financial investment in its manufacturer, from their aero engine business.
Advantages of these alloys were recognised worldwide. When 576 pistons in Hiduminium R.R.59 alloy were used for the Italian Marshal Balbo
's trans-Atlantic flight, High Duty Alloys used it in their own advertising.
in 1927.
The company began from the ruins of the World War I
aero engine builder, Peter Hooker Ltd. of Walthamstow
. Hookers license-built the Gnôme
engine and were better known as The British Gnôme and Le Rhône Engine Co. They had become expert at working Y alloy
. After some years in voluntary liquidation, the company was wound up in 1927. Simultaneously a large order was received, of some thousands of pistons for the Armstrong Siddeley Jaguar engine. Armstrong Siddeley
had no other capable source for these pistons, so W.C. Devereux, works manager of Hookers, proposed to set up a new company to complete this order. John Siddeley loaned the money to re-purchase the necessary equipment and re-employ some of the staff from Hookers. As the buildings had already been sold, the new company relocated to Slough
.
Demand from Rolls-Royce later led to expansion into a factory at Redditch
. These materials were so crucial to aircraft production that with the outbreak of World War II a shadow factory was established in the remote area of Westmoreland
(now Cumbria
), at Distington
, near Whitehaven
.
As well as producing ingots of raw alloy, manufacturing included the initial forging or casting processes. Finish machining would be undertaken by the customer. Hiduminium was so successful that during World War II it was in use by all of the major British aero engine makers.
In 1934 the Reynolds Tube Co.
began production of extruded structural components for airframes, using R.R.56 alloy supplied by High Duty Alloys. A new purpose-built plant was constructed at their works in Tyseley
, Birmingham
. In time, the post-war Reynolds company, already known for its steel bicycle frame
tubes, would attempt to survive in the peacetime market by supplying Hiduminium alloy components for high-end aluminium bicycle crank
s and brakes.
The 1,600 torches for the 1948 London Olympics
were cast by the company.
alloys had already demonstrated high-strength aluminium alloys. Y alloy
's virtue was its ability to maintain high strength at high temperatures. R.R alloys were developed by Hall & Bradbury at Rolls-Royce, partly to simplify the manufacture of components using them. A deliberate heat treatment process of multiple steps was used to control their physical properties.
In terms of composition, Y alloy typically contains 4% of copper and 2% of nickel. R.R. alloys reduce each of these by half to 2% and 1%, and 1% of iron is introduced.
Example composition:
. In contrast, R.R. alloys remain soft afterwards, until deliberately heat treated again by precipitation hardening for artificial ageing. This simplifies their machining in the soft state, particularly where component blanks are made by a subcontractor and must be shipped to another site before machining. For R.R.56 the solution treatment is to quench from 530°C and ageing is carried out at 175°C. For R.R.50, the solution treatment may be omitted and the metal taken directly to precipitation hardening (155°C-170°C).
After solution treatment, the tensile strength
of the alloy increases, but its Young's modulus
decreases. The second stage of artificial aging increases the strength slightly, but also restores or improves the modulus.
.
The number of alloys expanded to support a range of applications and processing techniques. At the Paris Airshow of 1953, High Duty Alloys showed no less than eight different Hiduminium R.R. alloys: 20, 50, 56, 58, 66, 77, 80, 90. Also shown were gas turbine
compressor and turbine blade
s in Hiduminium, and a range of their products in the Magnuminium alloy series.
R.R.58, comprising 2.5 copper, 1.5 magnesium, 1.0 iron, 1.2 nickel, 0.2 silicon, 0.1 titanium and the remainder aluminium, and originally intended for jet engine
compressor blades, was used as the main structural material for the Concorde
airframe, supplied by High Duty Alloys, it was also known as AU2GN to the French side of the project
Later alloys, such as R.R.66, were used for sheet, where high strength was needed in an alloy capable of being worked by deep drawing
. This became increasingly important with the faster jet aircraft post-war, as issues such as transonic compressibility became important. It was now necessary for an aircraft's covering material to be strong, not merely the spar or framing beneath.
R.R.350, a sand-castable high temperature alloy, was used in the General Electric YJ93
jet engine and was also used in the General Electric GE4 intended for the later cancelled American Boeing 2707
SST
project.
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...
s, developed for aircraft use by Rolls-Royce
Rolls-Royce Limited
Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....
before World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. They were manufactured and later developed by High Duty Alloys Ltd.. The name Hi-Du-Minium is derived from that of High Duty Alloys.
The first of these Hiduminium alloys was termed 'R.R.50' . This alloy was first developed for motor-racing 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, and was only later adopted for aircraft engine use. It was a development of the earlier 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....
, the first of the nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
-containing light 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...
s. These alloys are one of the three main groups of high-strength aluminium alloys, the nickel-aluminium alloys having the advantage of retaining strength at high temperatures, making them particularly useful for pistons.
Early adoption
The alloys were in limited use for aircraft by 1929, being used in the Rolls-Royce RRolls-Royce R
The Rolls-Royce R was a British aero engine designed and built specifically for air racing purposes by Rolls-Royce Limited. Nineteen R engines were assembled in a limited production run between 1929 and 1931...
engine that was successful in the Schneider Trophy
Schneider Trophy
The Coupe d'Aviation Maritime Jacques Schneider was a prize competition for seaplanes. Announced by Jacques Schneider, a financier, balloonist and aircraft enthusiast, in 1911, it offered a prize of roughly £1,000. The race was held eleven times between 1913 and 1931...
seaplane races. They quickly spread to other manufacturers, in 1931 being adopted by ABC
ABC Motors
ABC Motors Limited of Hersham, Surrey, England was a manufacturer of cars, aircraft, motor scooters, and engines for road and air. Established by Ronald Charteris in Hersham, Surrey in 1912, its chief designer was the young and talented Granville Bradshaw...
for their Hornet
ABC Hornet
|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6....
engine. R.R.50 alloy was used for the crankcase, R.R.53 for the pistons.
Their first mass production use was in the Armstrong Siddeley Special
Armstrong Siddeley
Armstrong Siddeley was a British engineering group that operated during the first half of the 20th century. It was formed in 1919 and is best known for the production of luxury motor cars and aircraft engines.-Siddeley Autocars:...
saloon car of 1933. Armstrong Siddeley already having had experience of the alloy, and financial investment in its manufacturer, from their aero engine business.
Advantages of these alloys were recognised worldwide. When 576 pistons in Hiduminium R.R.59 alloy were used for the Italian Marshal Balbo
Italo Balbo
Italo Balbo was an Italian Blackshirt leader who served as Italy's Marshal of the Air Force , Governor-General of Libya, Commander-in-Chief of Italian North Africa , and the "heir apparent" to Italian dictator Benito Mussolini.After serving in...
's trans-Atlantic flight, High Duty Alloys used it in their own advertising.
High Duty Alloys Ltd.
High Duty Alloys Ltd. was founded at Farnham Road, SloughSlough
Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...
in 1927.
The company began from the ruins of the 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...
aero engine builder, Peter Hooker Ltd. of Walthamstow
Walthamstow
Walthamstow is a district of northeast London, England, located in the London Borough of Waltham Forest. It is situated north-east of Charing Cross...
. Hookers license-built the Gnôme
Gnome Monosoupape
The Monosoupape , was a rotary engine design first introduced in 1913 by Gnome Engine Company...
engine and were better known as The British Gnôme and Le Rhône Engine Co. They had become expert at working 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....
. After some years in voluntary liquidation, the company was wound up in 1927. Simultaneously a large order was received, of some thousands of pistons for the Armstrong Siddeley Jaguar engine. Armstrong Siddeley
Armstrong Siddeley
Armstrong Siddeley was a British engineering group that operated during the first half of the 20th century. It was formed in 1919 and is best known for the production of luxury motor cars and aircraft engines.-Siddeley Autocars:...
had no other capable source for these pistons, so W.C. Devereux, works manager of Hookers, proposed to set up a new company to complete this order. John Siddeley loaned the money to re-purchase the necessary equipment and re-employ some of the staff from Hookers. As the buildings had already been sold, the new company relocated to Slough
Slough
Slough is a borough and unitary authority within the ceremonial county of Royal Berkshire, England. The town straddles the A4 Bath Road and the Great Western Main Line, west of central London...
.
Demand from Rolls-Royce later led to expansion into a factory at Redditch
Redditch
Redditch is a town and local government district in north-east Worcestershire, England, approximately south of Birmingham. The district had a population of 79,216 in 2005. In the 19th century it became the international centre for the needle and fishing tackle industry...
. These materials were so crucial to aircraft production that with the outbreak of World War II a shadow factory was established in the remote area of Westmoreland
Westmoreland
Westmoreland is a historic county in England. It may also refer to:-Places:Australia*Westmoreland County, New South WalesCanada*Westmorland County, New BrunswickJamaica*Westmoreland, Jamaica, a parishNew Zealand...
(now Cumbria
Cumbria
Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in...
), at Distington
Distington
Distington is a large village and civil parish in Cumbria, England, south of Workington and north-northeast of Whitehaven.Historically a part of Cumberland, the civil parish includes the nearby settlements of Common End, Gilgarran and Pica...
, near Whitehaven
Whitehaven
Whitehaven is a small town and port on the coast of Cumbria, England, which lies equidistant between the county's two largest settlements, Carlisle and Barrow-in-Furness, and is served by the Cumbrian Coast Line and the A595 road...
.
As well as producing ingots of raw alloy, manufacturing included the initial forging or casting processes. Finish machining would be undertaken by the customer. Hiduminium was so successful that during World War II it was in use by all of the major British aero engine makers.
In 1934 the Reynolds Tube Co.
Reynolds Cycle Technology
Reynolds Cycle Technology is a manufacturer of tubing for bicycle frames and other bicycle components based in Birmingham, England established in 1898.-History:...
began production of extruded structural components for airframes, using R.R.56 alloy supplied by High Duty Alloys. A new purpose-built plant was constructed at their works in Tyseley
Tyseley
Tyseley is a district in the southern half of the city of Birmingham, England, near the Coventry Road and the districts of Small Heath and Yardley...
, Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
. In time, the post-war Reynolds company, already known for its steel bicycle frame
Bicycle frame
A bicycle frame is the main component of a bicycle, on to which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles, a main triangle and a paired rear triangle...
tubes, would attempt to survive in the peacetime market by supplying Hiduminium alloy components for high-end aluminium bicycle crank
Crankset
The crankset or chainset , is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain, which in turn drives the rear wheel...
s and brakes.
The 1,600 torches for the 1948 London Olympics
1948 Summer Olympics
The 1948 Summer Olympics, officially known as the Games of the XIV Olympiad, were an international multi-sport event which was held in London, England, United Kingdom. After a 12-year hiatus because of World War II, these were the first Summer Olympics since the 1936 Games in Berlin...
were cast by the company.
Alloy composition
The DuraluminDuralumin
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%...
alloys had already demonstrated high-strength aluminium alloys. 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....
's virtue was its ability to maintain high strength at high temperatures. R.R alloys were developed by Hall & Bradbury at Rolls-Royce, partly to simplify the manufacture of components using them. A deliberate heat treatment process of multiple steps was used to control their physical properties.
In terms of composition, Y alloy typically contains 4% of copper and 2% of nickel. R.R. alloys reduce each of these by half to 2% and 1%, and 1% of iron is introduced.
Example composition:
| R.R.56 | |
|---|---|
| Melting point | 635°C |
| Density | 2.75 |
| Composition | |
| Copper Copper Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish... |
2.0% |
| Nickel Nickel Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile... |
1.3% |
| Magnesium Magnesium Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole... |
0.8% |
| Iron Iron Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust... |
1.4% |
| 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.... |
0.1% |
| Silicon Silicon Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table... |
0.7% |
| Aluminium Aluminium Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances.... |
93.7% |
Heat treatment
As for many of the aluminium alloys, Y alloy age hardens spontaneously at normal temperatures after solution heat treatingQuench
In materials science, quenching is the rapid cooling of a workpiece to obtain certain material properties. It prevents low-temperature processes, such as phase transformations, from occurring by only providing a narrow window of time in which the reaction is both thermodynamically favorable and...
. In contrast, R.R. alloys remain soft afterwards, until deliberately heat treated again by precipitation hardening for artificial ageing. This simplifies their machining in the soft state, particularly where component blanks are made by a subcontractor and must be shipped to another site before machining. For R.R.56 the solution treatment is to quench from 530°C and ageing is carried out at 175°C. For R.R.50, the solution treatment may be omitted and the metal taken directly to precipitation hardening (155°C-170°C).
After solution treatment, the tensile strength
Tensile strength
Ultimate tensile strength , often shortened to tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, which is when the specimen's cross-section starts to significantly contract...
of the alloy increases, but its Young's modulus
Young's modulus
Young's modulus is a measure of the stiffness of an elastic material and is a quantity used to characterize materials. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. In solid mechanics, the slope of the stress-strain...
decreases. The second stage of artificial aging increases the strength slightly, but also restores or improves the modulus.
| R.R.53 B, chill cast | ||
|---|---|---|
| Maximum Stress Tons/sq in. | Strain (elongation) |
|
| As cast | 14 | 3% |
| Solution treated | 22 | 6% |
| Solution treated and artificially aged |
26 | 3% |
| Composition, R.R.53 B | |
|---|---|
| Copper | 2.5% |
| Nickel | 1.5% |
| Magnesium | 0.8% |
| Iron | 1.2% |
| Silicon | 1.2% |
| Aluminium | 92.8% |
Alloy range
A range of alloys were produced in the R.R.50 range. These could be worked by casting or forging, but they were not intended for rolling as sheet or general machining from bar stockBar stock
Bar stock, also colloquially known as billet, is a common form of raw purified metal, used by industry to manufacture metal parts and products....
.
| R.R. 50 | General-purpose 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... alloy |
| R.R. 53 | Die-cast 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... piston alloy |
| R.R. 56 | General-purpose forging Forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons... alloy |
| R.R. 59 | Forged piston alloy |
The number of alloys expanded to support a range of applications and processing techniques. At the Paris Airshow of 1953, High Duty Alloys showed no less than eight different Hiduminium R.R. alloys: 20, 50, 56, 58, 66, 77, 80, 90. Also shown were gas turbine
Gas turbine
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....
compressor and turbine blade
Turbine blade
A turbine blade is the individual component which makes up the turbine section of a gas turbine. The blades are responsible for extracting energy from the high temperature, high pressure gas produced by the combustor. The turbine blades are often the limiting component of gas turbines...
s in Hiduminium, and a range of their products in the Magnuminium alloy series.
R.R.58, comprising 2.5 copper, 1.5 magnesium, 1.0 iron, 1.2 nickel, 0.2 silicon, 0.1 titanium and the remainder aluminium, and originally intended for jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
compressor blades, was used as the main structural material for the Concorde
Concorde
Aérospatiale-BAC Concorde was a turbojet-powered supersonic passenger airliner, a supersonic transport . It was a product of an Anglo-French government treaty, combining the manufacturing efforts of Aérospatiale and the British Aircraft Corporation...
airframe, supplied by High Duty Alloys, it was also known as AU2GN to the French side of the project
Later alloys, such as R.R.66, were used for sheet, where high strength was needed in an alloy capable of being worked by deep drawing
Deep drawing
Deep drawing is a sheet metal forming process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch. It is thus a shape transformation process with material retention. The process is considered "deep" drawing when the depth of the drawn part exceeds...
. This became increasingly important with the faster jet aircraft post-war, as issues such as transonic compressibility became important. It was now necessary for an aircraft's covering material to be strong, not merely the spar or framing beneath.
R.R.350, a sand-castable high temperature alloy, was used in the General Electric YJ93
General Electric YJ93
-See also:-External links:...
jet engine and was also used in the General Electric GE4 intended for the later cancelled American Boeing 2707
Boeing 2707
The Boeing 2707 was developed as the first American supersonic transport . After winning a competition for a government-funded contract to build an American SST, Boeing began development at its facilities in Seattle, Washington...
SST
SST
The acronym SST may refer to:In aircraft and naval vehicles*Scaled Composites SpaceShipTwo*SST class blimp SS class blimp*Supersonic transport , civil aircraft for transporting passengers faster than the speed of sound....
project.