How strong is compacted graphite iron?
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While not quite as strong as ductile iron, CGI is 75 percent stronger and up to 75 percent stiffer than gray iron. The thermal and damping characteristics of CGI are midway between ductile and gray iron.
What is compact graphite cast iron?
Compacted Graphite Iron, which is also known as CGI or Vermicular Graphite Iron, is a form of cast iron in which the shape of the graphite particles is between that of conventional grey iron flakes and ductile iron where the graphite is in spheres.
How do you make compacted graphite iron?
Similar to ductile iron, compacted graphite iron is produced by adding magnesium to a desulfurized base iron. As shown in Figure 3, CGI is stable over a range of approximately 0.008% magnesium (Mg), which is approximately five times smaller than the commercially used Mg-range for ductile iron.
What is compacted graphite cast iron used for?
Abstract. CGI – Compacted Graphite Iron – has reached an important status for automotive industry, mainly in the last ten years. The material has been used for manufacturing parts as brake discs, exhaust manifolds, engine heads and diesel engine blocks.
Is compacted graphite iron lighter than aluminum?
-Far more fatigue resistant than Aluminum in higher temperatures. -Due to CGI’s high strength, it can technically be machined to be lighter than aluminum while maintaining the same strength levels (although generally, CGI blocks are not machined this far in order to keep strength levels high).
How do you make cast iron malleable?
Detailed Solution. Malleable Cast Iron: Malleable cast iron is produced from white cast iron by annealing. During annealing treatment graphite nucleates and grows from the Fe 3C to form nodules, 900-950°C for many days / cooling slowly.
What is SGI material?
In SG Cast Iron the graphite is in the form of spherical nodules (hence the name Spheroidal Graphite) rather than flakes as in Grey Iron. This nodular graphite structure inhibits the creation of linear cracks hence the ability to withstand distortion.
What are Ford engine blocks made of?
Engineers cleverly designed what Ford calls a two-piece block with the iron sandwiched between aluminum heads and a thick die-cast-aluminum “ladder frame.” The oil pan is molded plastic. No cylinder liners or expensive bore-surface treatments are needed inside the strong CGI, a significant cost savings.
What is GREY cast iron used for?
It is the most common cast iron and the most widely used cast material based on weight. It is used for housings where the stiffness of the component is more important than its tensile strength, such as internal combustion engine cylinder blocks, pump housings, valve bodies, electrical boxes, and decorative castings.
What temperature does cast iron become malleable?
Malleable cast iron Malleable iron starts as a white iron casting that is then heat treated for a day or two at about 950 °C (1,740 °F) and then cooled over a day or two.
How strong is malleable iron?
Malleable iron fittings are lighter fittings in 150# and 300# pressure class. They are made for light industrial and plumbing use up to 300 psi.
What is full form of SG iron?
SG Iron is also known as Ductile Cast Iron, Nodular Cast Iron, Spheroidal Graphite Iron and Spherulitic Cast Iron. This grade of Iron was developed over 60 years ago and in the USA. As the name Ductile Iron suggests this grade of Cast Iron has a degree of ductility.
What is compact compacted graphite iron?
Compacted Graphite Iron, which is also known as CGI or Vermicular Graphite Iron, is a form of cast iron in which the shape of the graphite particles is between that of conventional grey iron flakes and ductile iron where the graphite is in spheres.
Do microstructural changes affect the properties of compacted graphite iron?
While some material properties, such as Poisson’s ratio or thermal expansion, are effectively constant over a wide range of microstructure and chemistry, the present study addresses the effect of microstructural changes on the properties of compacted graphite iron.
Why is compacted graphite used for engine design?
Ultimately, the compacted graphite morphology inhibits both crack initiation and propagation and is the source of the improved mechanical properties relative to grey cast iron. Compacted Graphite Iron: Mechanical and Physical Properties for Engine Design
What are the physical properties of graphite Irons?
The worm-like compacted-graphite shape provides physical properties that mirror the most beneficial properties of grey and ductile irons. Grey iron is particularly easy to cast and machine and it has good damping and thermal conductivity, but its flaky structure makes it brittle, as reflected by its low tensile strength.