Ferrium C64Ferrium C64 (AMS 6509) is a new high strength, high
surface hardness, good fracture toughness carburizable steel that
also has high temperature resistance, corrosion resistance and
hardenability. C64 steel is a higher performance upgrade from 9310,
Pyrowear 53, EN36A, EN36B, EN36C and 8620. It can achieve a surface
hardness of 62-64 Rockwell C (HRC) via vacuum carburization.C64
steel is double vacuum melted (i.e., vacuum induction melted and
then vacuum arc remelted or "VIM/VAR") so that it is very clean,
which helps it have a much greater fatigue strength.ApplicationsOne
leading application for C64 steel is as an upgrade from Pyrowear 53
steel in demanding Bell Helicopter transmission gear boxes. Under
an Army-funded FARDS program, Bell has produced and is testing in
2013-14 a demonstrator gear box. Benefits include greater
temperature resistance, pitting resistance and corrosion
resistance.Other applications can include racing transmission
gears, gears with integral bearing races, integrally-geared
driveshafts, bearings, actuators, and other power transmission
components where durability, compactness, weight savings, high
temperature resistance or high surface fatigue resistance is
valued.If you need even greater strength and fracture toughness in
a carburizing-grade steel, see Ferrium C61.BenefitsBenefits of
using C64 steel vs. alloys such as 9310/EN36, Pyrowear Alloy 53
("X53"), or 8620 for power transmission applications can include:
Smaller, lighter-weight gears (including gears with integral
bearing races), or greater throughput or durability, including
improving existing gears by replacing current materials with C64
steel. Gears and gearboxes using C64 steel can often handle
approximately 15% higher loads than comparable designs using
traditional materials, or be reduced in size and weight by
comparable amounts, due in part to C64 steel's excellent surface
contact fatigue resistance and bending fatigue resistance.
Conventional gear steels such as 9310 or 8620 cannot typically
achieve 62-64 Rockwell C Hardness case hardness with a
fatigue-resistant microstructure. The combination of high surface
hardness and excellent gear fatigue properties also makes C64 steel
an attractive new option for gears that incorporate integral
bearing races (e.g. planetary gears in epicyclical transmissions).
Smaller, lighter-weight driveshafts, or greater throughput or
durability, including improving existing driveshafts by replacing
current materials with C64 steel. Integrally-geared driveshafts
using C64 steel can often handle approximately 20-25% higher loads
than comparable driveshafts using traditional materials, or be
reduced in size and weight by comparable amounts. C64 steels core
UTS of 229 ksi is a ~31% increase vs. 9310, for example. Reduced
manufacturing times and costs, with increased flexibility and
control. C64 steel was designed to resist grain growth even at high
temperatures, have high hardenability, and use vacuum carburizing
with a direct low pressure gas quench, to thus: maintain good
properties in large, thick-sectioned components (even with vacuum
carburizing); reduce final machining/finishing costs by eliminating
intergranular oxide formation and reducing quench distortion;
eliminate the time, expense, equipment and non-uniformity of the
traditional after-carburizing oil quench hardening step; and permit
dial-in control of carburized case hardness profiles. AGMA
technical paper 11FTM27 provides a detailed comparison of costs and
time (see below). Superior high temperature operability and
survivability such as in oil-out emergency conditions or
high-temperature environments. The 925F tempering temperature of
C64 steel is 400-600F higher than most incumbent alloys, yielding
superior thermal stability and allowing gearboxes to run hotter
(thus reducing cooling system weight, size, drag, etc.). Greater
corrosion resistance. Under a Navy-funded project, QuesTek has
shown C64 steel's corrosion resistance to be greater than that of
both 9310 and Pyrowear 53.BronzeBronze is an alloy consisting
primarily of copper, usually with tin as the main additive. It is
hard and tough, and it was so significant in antiquity that the
Bronze Age was named after the metal. Because historical pieces
were often made of brasses (copper and zinc) and bronzes with
different compositions, modern museum and scholarly descriptions of
older objects increasingly use the more inclusive term "copper
alloy" instead.[1] Historically the term latten was used for such
alloys.The word bronze (173040) is borrowed from French bronze
(1511), itself borrowed from Italian bronzo "bell metal, brass"
(13th century) (transcribed in Medieval Latin as bronzium), from
either:PropertiesTypically bronze only oxidizes superficially; once
a copper oxide (eventually becoming copper carbonate) layer is
formed, the underlying metal is protected from further corrosion.
However, if copper chlorides are formed, a corrosion-mode called
"bronze disease" will eventually completely destroy it.[17]
Copper-based alloys have lower melting points than steel or iron,
and are more readily produced from their constituent metals. They
are generally about 10 percent heavier than steel, although alloys
using aluminium or silicon may be slightly less dense.
Bronzes are softer and weaker than steelbronze springs, for
example, are less stiff (and so store less energy) for the same
bulk. Bronze resists corrosion (especially seawater corrosion) and
metal fatigue more than steel and is a better conductor of heat and
electricity than most steels. The cost of copper-base alloys is
generally higher than that of steels but lower than that of
nickel-base alloys.Copper and its alloys have a huge variety of
uses that reflect their versatile physical, mechanical, and
chemical properties. Some common examples are the high electrical
conductivity of pure copper, the low-friction properties of bearing
bronze (bronze which has a high lead content 6-8%), the resonant
qualities of bell bronze (20% tin, 80% copper), and the resistance
to corrosion by sea water of several bronze alloys.The melting
point of bronze varies depending on the ratio of the alloy
components and is about 950C (1,742F). Bronze may be nonmagnetic,
but certain alloys containing iron or nickel may have magnetic
properties.Belt (mechanical)
A pair of vee-belts
flat belt
Flat belt drive in the machine shop at the Hagley MuseumA belt
is a loop of flexible material used to mechanically link two or
more rotating shafts, most often parallel. Belts may be used as a
source of motion, to transmit power efficiently, or to track
relative movement. Belts are looped over pulleys and may have a
twist between the pulleys, and the shafts need not be parallel. In
a two pulley system, the belt can either drive the pulleys normally
in one direction (the same if on parallel shafts), or the belt may
be crossed, so that the direction of the driven shaft is reversed
(the opposite direction to the driver if on parallel shafts). As a
source of motion, a conveyor belt is one application where the belt
is adapted to continuously carry a load between two
points.Standards for useThe open belt drive has parallel shafts
rotating in the same direction, whereas the cross-belt drive also
bears parallel shafts but rotate in opposite direction. The former
is far more common, and the latter not appropriate for timing and
standard V-belts unless there is a twist between each pulley so
that the pulleys only contact the same belt surface. Nonparallel
shafts can be connected if the belt's center line is aligned with
the center plane of the pulley. Industrial belts are usually
reinforced rubber but sometimes leather types, non-leather
non-reinforced belts, can only be used in light applications.The
pitch line is the line between the inner and outer surfaces that is
neither subject to tension (like the outer surface) nor compression
(like the inner). It is midway through the surfaces in film and
flat belts and dependent on cross-sectional shape and size in
timing and V-belts. Calculating pitch diameter is an engineering
task and is beyond the scope of this article. The angular speed is
inversely proportional to size, so the larger the one wheel, the
less angular velocity, and vice versa. Actual pulley speeds tend to
be 0.51% less than generally calculated because of belt slip and
stretch. In timing belts, the inverse ratio teeth of the belt
contributes to the exact measurement. The speed of the belt
is:Speed = Circumference based on pitch diameter angular speed in
rpm
Advantages/DisadvantagesAdvantages:
Small amount of installation work Low maintainance High
reliability In some applications, shock and sound absurption
Transmission of power over long distances
Disadvantages: Limited power transmission. If very large ratios
ofspeed reduction are required in the drive, gearreducers are
desirable because they can typicallyaccomplish large reductions in
a rather smallpackage.
Direct-shift gearboxThis article is about the Volkswagen Group
dual-clutch transmissions. For dual-clutch transmissions in
general, see Dual-clutch transmission.
Part-cutaway view of the Volkswagen Group 6-speed Direct-Shift
Gearbox. The concentric multi-plate clutches have been sectioned,
along with the mechatronics module. This also shows the additional
power take-off for distributing torque to the rear axle for
four-wheel drive applications. - View this image with
annotations
Schematic diagram of a dual clutch transmission
Dual-clutch gearbox:M: MotorA: Primary driveB: Double ClutchC:
shaftD: main shaft, even gearsE: main shaft, odd gearsF: OutputA
direct-shift gearbox commonly abbreviated to DSG, is an
electronically controlled dual-clutch multiple-shaft manual
gearbox, in a transaxle design without a conventional clutch pedal,
and with full automatic, or semi-manual control. The first actual
dual-clutch transmissions derived from Porsche in-house development
for 962 racing cars in the 1980s.In simple terms, a DSG is two
separate manual gearboxes (and clutches), contained within one
housing, and working as one unit. It was designed by BorgWarner,[4]
and was initially licensed to the Volkswagen Group, with support by
IAV GmbH.[citation needed] By using two independent clutches,[2][5]
a DSG can achieve faster shift times,[2][5] and eliminates the
torque converter of a conventional epicyclic automatic
transmission.[2]
Advantages Better fuel economy[2][6] (up to 15% improvement)
than conventional planetary geared automatic transmission (due to
lower parasitic losses from oil churning)[5] and for some models
with manual transmissions;[2] No loss of torque transmission from
the engine to the driving wheels during gear shifts;[2][4][5] Short
up-shift time of 8milliseconds when shifting to a gear the
alternate gear shaft has preselected;[3][4] Smooth gear-shift
operations;[4][5] Consistent down-shift time of 600milliseconds,
regardless of throttle or operational mode;[4]Disadvantages
Achieving no acceleration or hill climbing, while avoiding engine
speeds higher than a certain limit (e.g. 3000 or 4000 RPM), is
difficult since it requires avoiding triggering the
kick-down-switch. Avoiding triggering the kick-down-switch requires
a good feel of the throttle pedal, but use of full throttle can
still be achieved with a little sensitivity as the kick-down button
is only activated beyond the normal full opening of the accelerator
pedal.[citation needed] Marginally worse overall mechanical
efficiency compared to a conventional manual transmission,
especially on wet-clutch variants (due to electronics and hydraulic
systems);[5] Expensive specialist transmission fluids/lubricants
with dedicated additives are required, which need regular
changes;[14][15] Relatively expensive to manufacture,[citation
needed] and therefore increases new vehicle purchase price;
Relatively lengthy shift time when shifting to a gear ratio which
the transmission ECU did not anticipate (around 1100ms, depending
on the situation);[4][20] Torque handling capability constraints
perceive a limit on after-market engine tuning modifications
(though many tuners and users have now greatly exceeded the
official torque limits.[citation needed]); Later variants have been
fitted to more powerful cars, such as the 300bhp/350Nm VW R36 and
the 272 bp/350 Nm Audi TTS. Heavier than a comparable Getrag
conventional manual transmission (75kg (165lb) vs. 47.5kg
(105lb));
Magnesium alloy
Figure 1: Number of scientific articles with terms AZ91 or AZ31
in the abstract.Magnesium alloys are mixtures of magnesium with
other metals (called an alloy), often aluminium, zinc, manganese,
silicon, copper, rare earths and zirconium. Magnesium is the
lightest structural metal. Magnesium alloys have a hexagonal
lattice structure, which affects the fundamental properties of
these alloys. Plastic deformation of the hexagonal lattice is more
complicated than in cubic latticed metals like aluminium, copper
and steel. Therefore magnesium alloys are typically used as cast
alloys, but research of wrought alloys has been more extensive
since 2003. Cast magnesium alloys are used for many components of
modern cars, and magnesium block engines have been used in some
high-performance vehicles; die-cast magnesium is also used for
camera bodies and components in lenses.Practically all the
commercial magnesium alloys manufactured in the United States
contain aluminium (3 to 13 per cent) and manganese (0.1 to 0.4 per
cent). Many also contain zinc (0.5 to 3 per cent) and some are
hardenable by heat treatment. All the alloys may be used for more
than one product form, but alloys AZ63 and AZ92 are most used for
sand castings, AZ91 for die castings, and AZ92 for most used for
permanent mold castings (AZ63 and A10 are sometimes used). For
forgings, AZ61 is most used, with M1 employed where low strength is
required and AZ80 for highest strength. For extrusions, a wide
range of shapes, bars, and tubes is made from M1 alloy where its
low strength suffices or where welding to M1 castings is planned.
Alloys AZ31, AZ61, and AZ80 are employed for extrusions in the
order named, where their increase in strength justifies their
increased cost.[1][full citation needed]Magnox (alloy), whose name
is an abbreviation for 'magnesium non-oxidising', is 99% magnesium
and 1% aluminium, and used in the cladding of fuel rods in some
nuclear power stations.Magnesium alloys are referred to by short
codes (defined in ASTM B275) that denote the approximate chemical
composition by weight. For example, AS41 has 4% aluminium and 1%
silicon; AZ81 is 7.5% aluminium and 0.7% zinc. If aluminium is
present, manganese is almost always also there at about 0.2% by
weight to improve grain structure; if aluminium and manganese are
absent, zirconium is usually present at about 0.8% for the same
purpose.
Advantage :The main advantage of having magnesium in alloys is
its strength. Magnesium has a strength to weight ratio that is
similar to aluminum. It is often used when you want to cast a thick
nonload-baring part but want it to be fairly light.
Comparative and effective use of new Mg alloysNew light
materials are effectively nowadays inserted in world strategies of
automotive industry since the environment necessities for pollution
and reduction of fuel consumption. Therefore the industry takes
part of the risk of development of such alloys but, in fact, some
of this has been made at academic level. It's possible to enumerate
some aspects of the necessities and characteristics concerning
those alloys: low costs, insulation (sound and thermal), impact
safety, deformation strength, recyclability and guaranty (to aging
as example). All those aspects are linked with the increasing of
new automobile models and reflect in production programs more and
more complexes.Different joining techniques were applied to
magnesium wrought semi-finished products, in order to promote their
introduction on aeronautical structures. Airbus has performed some
first tests to join magnesium sheets by friction stir welding. In
general the alloy AZ31B (Mg-3.0%Al-0.3%Mn) is quite easily weldable
by different processes. Using laser beam welding an AZ61
(Mg-5.9%Al-0.5%Zn-0.2%Mn) filler wire is advantageous for the
mechanical properties to weld this alloy.Another influence in
research for new technologies of materials and light alloys relies
on the shortening of models life. New materials and alloys are
usually more expensive than commercial materials, so there is
direct needs of investment in reduce the costs of production and
development of such alloys allowing the utilization in large scale
in the automobile production processes.The increase in the
potential application of magnesium profiles is strongly dependent
on the question of whether established forming processes for
aluminum and steel can be changed to magnesium and its alloys.
Broad-spectrum applications of magnesium alloys in the automotive
industry are casting products.Despite the fact that the
introduction of light alloys and new technology light alloys is a
tendency not changeable, the utilization effective today still is
more applicable to competition or sportive cars and motorcycles,
due to the high costs previously mentioned. However if compared
along the existence of automobile the employment of light alloys
rise exponentially from the earliest up to the latest commercial
model. The influence of 1970's in the development of such
technologies is notable comparing with the few kilograms used in
the first automobiles.Recently the weightiness of light alloys, for
example, in an automobile is near 90 kg in Europe, 120 Kg in United
States and 42 kg in Brazil, but increasing year-to-year. Nearly 90%
or more from the weight relies on aluminum alloys, but there is a
rapidly increase in the magnesium and a slightly in titanium alloys
in the total amount used. All those factors contribute to new
researches and development of this class of materials for
structural and mechanical applications in automotive
industry.Traditionally the main usage for magnesium and magnesium
alloys has been for aluminum alloying, high pressure die casting
and steel desulphurization. Over the last 10 years the demand for
magnesium and its alloys has grown at an average rate close to 5%
per year. The die casting industry which expanded at a rate of over
10% per year was mainly responsible for this steady growth of the
whole industry. This remarkable growth was possible because of the
stable and relatively inexpensive supply of magnesium from China.
This low costs supply has changed at the end of 2007 and early
2008. During that period the base price of magnesium has tripled.
In this article present and future opportunity in supply and demand
of magnesium and magnesium alloys are examined. Special attention
will be given to the growth potential of magnesium alloys for
components which will be driven most likely by environmental
regulations from governments (Closset, 2008)As the lightest
structural materials, magnesium alloys are well suited for the car
industry and also good fuel economy is essential. The selection of
a new alloy for a vehicle component should be based on technical
requirements and targeted cost. In reality, this selection process
is complicated and depends very much on the relative weight given
to a specific property, which is part of the combined desired
properties and final targeted cost. This task becomes even more
complicated if alternative material systems such as aluminum alloys
are considered for the same applications.Several new magnesium
alloys have been developed recently for high temperature
applications to obtain an optimal combination of die castability,
creep resistance, mechanical properties, corrosion performance, and
affordability. Most of the new alloys can only partially meet the
required performance and cost. The ZE41 alloy (gravity-casting
applications) has moderate strength and creep resistance combined
with good castability. Although this alloy exhibits poor corrosion
resistance, it is still preferred for certain applications.Although
the most commonly used magnesium die-casting alloys are of the AZ
and AM series, improved elevated-temperature performance is
required (gearbox housing, intake manifolds, oil pans, transfer
cases, crankcases, oil pump housing). Insufficient creep strength
of alloys can causes poor bearing-housing contact, leading to oil
leaks and increased noise and vibration.The use of magnesium alloy
casting in the automobile industry expands at an impressive rate in
this decade, which can manage with the energy and environment
problems. Alloy AZ91 (Mg-9Al-0.8Zn-0.2Mn) is the most favored
magnesium alloy, being used in approximately 90% of all magnesium
cast products (Guangyina et al., 2000).There are two patented
magnesium alloys (Dead Sea Magnesium Ltd, 2012): Mg-Al-Ca-Sr based
alloy (MRI 153M) and Mg-Al-Ca-Sr-Sn based alloy (MRI 230D). The MRI
153M is a beryllium-free, creep-resistant alloy capable of long
operation at temperatures up to 150C under high stresses
(substantially superior to those of commercial alloys). The MRI
230D is a die-casting alloy developed for use in automotive engine
blocks operating at temperatures up to 190C. The alloy has
excellent creep resistance combined with good castability, high
strength, and superior corrosion behavior. The results obtained
show that MRI 230D and A380 exhibit similar tensile creep behavior
at 150175C under stress of 70 MPa (Aghion, 2003).Concerning the
whole aeronautic industry, due to the fact that weight reduction is
a very important objective for strengthening the competitiveness,
several alternatives to obtain weight reduction has to be
investigated (welded or bonded airframes; use of metal laminates;
structural plastics; fiber reinforced composites).The non-metallic
materials application in selected areas is not conceivable due to
restricted properties under low or elevated temperatures, missing
electrical conductivity or low damage acceptance. Fiber reinforced
plastics are a relatively lavish material only used for primary
structure applications with highest demands.The family of magnesium
alloys and especially magnesium wrought materials can be an
excellent alternative because of their low density, good mechanical
properties, moderate cost and metallic character (in respect of
manufacturing, repair, maintenance compared to composites).In the
past decade a lot of research activities and development projects
have been carried out working on magnesium cast materials mainly
for transport applications. There were only very few activities on
magnesium wrought products like sheets, extrusions or forged parts.
The alloy spectrum of magnesium wrought alloys is still very
restricted.Aeronautic requirements and applications of wrought
products have been evaluated only in a few projects. Increasing the
research on magnesium wrought alloys will promote a new class of
metallic materials for aeronautical applications to win the
competition against plastics and fiber reinforced plastics.
Therefore, the variety of offered metallic materials will be
enlarged, not only for aircrafts, but also for space, military and
satellites applications.To reach this objective magnesium has to
deliver meaningfully higher weight specific mechanical properties
compared to aluminum. The aims for aluminum replacement can be
divided into two different steps in respect of time scale and
risk.A replacement of medium strength 5XXX aluminum alloys for
cockpit and cabin applications and another possible replacement of
medium to high strength 2XXX aluminum alloys for secondary
structure or non-pressurized fuselage applications.Forming and
joining technologies require development, simulation and validation
for the innovative material and technologies commonly used within
aeronautic industry. Recently Hombergsmeier presented the
requirements of new alloys concerning property temperature systems
and structural