This is due to its advantages in combining the benefits of gray and ductile cast iron. The relationships between the relevant laser cladding parameters. Jan 01, 2008 challenges in cutting cgi compacted graphite iron is increasingly used for diesel and racing engine components. This describes a range of cast irons where the graphite forms round ended flakes rather than sharp flakes or spheres. The effect of compacted graphite iron microstructure. As a stronger material that can absorb more power, cgi offers the improved performance and fuel economy to meet new emissions standards and the. An improved understanding of solidification of compacted graphite iron cgi is necessary to predict shrinkage related casting defects. The compacted graphite morphology inhibits crack initiation and growth and is the source of the improved mechanical properties relative to grey iron. The difference between the three types of graphite is more striking when viewed in the threedimensional deepetch scanning electron micrographs. Nevertheless, the complex 3d morphology of compacted graphite cg has hindered significant advances in similar theories for this type of graphite. To bring clarity to this issue, interrupted solidification.
As machining is conceptually a controlled fracture process, this stage comprehensively studies and models the initiation and propagation of fracture in compacted graphite iron. While it is known that cgi provides at least 70% higher tensile strength, 35% higher elastic modulus and 80% higher fatigue limits than conventional grey cast iron, the objective of this paper was to determine how the properties change with varying nodularity graphite shape and pearlite content. Effects of chip morphology on too life in highthroughput. The main output files from the simulation concerning cgi are. The wormlike compacted graphite shape provides physical properties that mirror the most. The compacted graphite iron graphite particles are formed in a vermicular shape, as shown in figure 1. Gusseisen mit vermiculargraphit especially in nonenglish speaking countries, is a metal which is gaining popularity in applications that require either greater strength, or lower weight than cast iron. Compacted graphite iron cgi is a form of cast iron which has elongated graphite particles mixed with spherical graphite particles present within the alloy, as opposed to the graphite flakes present in typical cast iron. Ductile iron compacted graphite iron cgi castings sds sc000042 rev 12 page 1 of 6 20 american foundry society meets the requirements of osha standard 29 cfr 1910. The second phase serves as an application of the previously built model to capture the more complex scenario involving machining of cgi at different cutting.
Compacted graphite iron a material solution for modern diesel engine cylinder blocks and heads dr steve dawson sintercast, sweden op19 the demands for improved fuel economy, performance and emissions continue to pose challenges for engine designers and the materials they choose. Compacted graphite iron cgi cubic boron nitride cbn 1 introduction compacted graphite iron cgi, belonging to the family of cast irons, has emerged as a candidate material to substitute gray cast iron ci in engine block applications for diesel engines because of superior mechanical properties, and. The 1st in our series of technical introduction articles focuses on the growing use of compacted graphite iron cgi. The shape of the graphite particles present in cgi greatly enhance the strength and hardness of the iron. Metallurgical process control for compacted graphite irons general introduction compacted vermicular graphite irons cgi have been produced since the inception of spheroidal graphite nodular or ductile irons in the late 1940s. Astm a84210 standard specification for compacted graphite iron castings. The change of graphite shape from flakelike in gray iron to compacted in cgi and spheroidal in nodular, or ductile, iron is a function of the amount of magnesium modification. Better strength of cgi, as compared to flake graphite iron fgi, allows cgi engine to perform at. Compacted graphite iron cgi has an important role in manufacturing of new generation engines.
Microstructure specifications typically require a nodularity range of 020%. Dec 17, 2015 new richmond, bridgnorth and stockholm, 17 december 2015 engineered propulsion systems eps has uniquely leveraged the strength and stiffness of compacted graphite iron cgi, together with a. Castability, product design, and production of compacted. Compacted graphite iron cylinder blocks and heads have become a vital part in todays modern diesel engine production, essential for manufacturers wishing to maintain a competitive edge. The test results are in good agreement with those in the reference 9. Pdf effect of holding time, thickness and heat treatment. This graphite structure and the resulting properties of the iron are intermediate between gray and ductile irons. Production experience with compacted graphite iron.
Cutting developments make application now practical. Configuration aluminum block and head 60degree v6, compacted graphite iron aluminum block, aluminum head manufacturing location cleveland engine plant lima engine plant intake manifold composite shellwelded with runner pack composite shellwelded with runner pack exhaust manifold threeport integrated into aluminum head integrated into. The mechanical and physical properties of compacted graphite iron cgi have been studied. In a recent paper discussing cgi uses for engine cylinder blocks and heads, s. The change in graphite morphology from the flake graphite fg in the base iron to the cg in the final iron is achieved by liquid treatment with different. The difference in these types of iron is the characteristics of the graphite used in the material. The compacted graphite cast construction allows for a max operating pressure of 3500psi. Engineered propulsion systems leverages cgi for diesel. Proposal of characterization procedure of metalgraphite. Compacted graphite iron is the material of choice for engine cylinder heads of heavyduty trucks. Dawson 2001 stated that the iron age is just beginning and we have taken this statement for the present paper.
Waupaca foundry produces various grades of gray, ductile and compacted graphite iron castings. Theory of crystallization, compacted graphite iron, ausferrite, dta method 1. Compacted graphite iron a material solution for modern. The relative properties of the three cast irons are summarized in table i. A number in parentheses indicates the year of last reapproval. Types of cast iron compacted graphite iron it is formed after adding small amount of mg andor ce to gray cast iron. Technical introduction to metallurgical process control. Horizontal cnc machining of compacted graphite iron cgi.
Pdf machinability of compacted graphite iron cgi and. Compacted graphite iron provides the best possible compromise between optimum mechanical properties, compared to. Sintercast will focus on providing process control technology, knowhow and technical support for the reliable high volume production of compacted graphite iron. Compacted graphite iron an overview sciencedirect topics. In 1949, a now wellknown material called ductile iron was patented. Gray iron, compacted graphite iron, and ductile iron are differentiated by the shape of the graphite particles figure 2. Materials may be used asis or alloyed to provide microstructures with different life and stabilities at elevated temperatures. Metallurgical process control for compacted graphite irons. Al, ti, mg and s, have the decisive importance for crystallization of compacted graphite and its share in casting structure. This article discusses the chemical composition, castability, mechanical properties at room temperature and elevated temperature, and physical properties of compacted graphite cg cast iron. Pearlite content can be chosen to suit the application.
Wear mechanism when machining compacted graphite iron e. Interchangeable with the very popular va and vg series hydraulic valve available in individual components or we can build you a custom engineered and tested valve assembly 100% factory tested. Compacted graphite iron is also known as cgi and vermicular graphite iron. Platt, quaker chemical corporation, metalworking division laboratory scope. Compacted graphite iron is an emerging cylinder block material having a higher specific strength than conventional gray iron, and with improved fatigue strength and acoustic properties relative to aluminum, thereby allowing cast iron blocks of reduced thickness and mass to be constructed tholl 1996. Graphite nucleation in compacted graphite cast iron. Cgi became commercially available as dependable methods for its production were developed. Compacted graphite cast irons russell ductile casting. Metallography and microstructures of cast iron janina m. Astm a84211a standard specification for compacted graphite. Compacted graphite iron cast iron with vermicular graphite is commonly named as such due to its wormlike graphite structure wormshaped vermicular, latin.
Pdf the compacted graphite iron cgi represents an example of material with remarkable and unexplored properties, especially in terms of. Gray iron is called that because when it is fractured, its surface appears a dull gray color. The resulting increase in thermal and mechanical loading has required a change from conventional grey cast iron to compacted graphite iron cgi in order to. Although compacted graphite iron has been known for more than four decades, the absence of a reliable massproduction technique has resulted in relatively. Invariably the structure was produced by accident and still is due to the breakdown of process control during. Sep 04, 2007 this video is of a makino hightorque horizontal machining center plunge and helical finish boring automotive engine blocks made of compacted graphite iron cgi. The mechanical and physical properties of compacted graphite iron. This gives a range of irons that have toughness with good heat transfer and vibration properties.
The full sintercast cgi material property database is available to sintercasts customers and has also been used as the basis of the chapter entitled mechanical properties of compacted graphite iron in the recently published afs american foundry society iron castings engineering handbook. These individual particles are elongated and randomly oriented, in a similar way as in grey iron, despite being shorter and thicker then these last ones, as well as having rounded edges 6. Casting process simulation of compacted graphite iron 03. Technical introduction to metallurgical process control for. Influence of fading on characteristics of thermal analysis. University of groningen thick cobased coating on cast. Schulz 1 institute of production management, technology and machine tools ptw university of technology, darmstadt, germany abstract the industrial application of compacted graphite iron in the automotive industry is taking a rather long time due to its uneconomic machinability, because of a significant decrease.
Compacted graphite iron cgi continues to gain use within the automotive industry. The improved mechanical properties of compacted graphite iron relative to conventional gray iron allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. It has inadvertently been produced in the past as a result of insufficient magnesium or cerium levels in molten intended. Sintercast will also develop and promote novel technologies beyond the core cgi market, including tracking and traceability solutions and other precision measurement products that bring enhanced control and profitability to the.
Compacted graphite iron cgi along with lamellar graphite iron and spheroidal graphite iron define the three main classes of cast iron according to morphology. C 300 to 375 350 to 425 400 to 475 450 to 525 500 to 575 100. Rotary cutting tools star su pressure coolant reamers utilize pressurized coolant to force chips ahead of the tool to produce ultrasmooth, ultraprecise holes. This project did not address the risk for the formation of lamellar graphite. Compacted vermicular graphite irons cgi have been produced since the inception of spheroidal graphite nodular or ductile irons in the late 1940s. A study of compacted graphite iron production in a laboratory environment was conducted by. Gray iron is the most widely cast metal and is easier to cast and less costly to produce than other types of cast iron because it neither requires special alloy additions necessary to produce ductile iron or compacted graphite iron nor does it require annealing heat treatment of the rough castings as is necessary to produce malleable iron. At the same time, a lesserknown material called compacted graphite iron cgi was also patented, though it was just considered a curiosity at the time. The material is being used for the manufacture of brake disks, exhaust manifolds, cylinder. In professional circles, this material is called compacted graphite iron cgi. Casting process simulation of compacted graphite iron 03025. 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.
A reliable and consistent production technology for high volume. In comparison to either grey iron or ductile iron, the entangled compacted graphite clusters interlock themselves into the iron matrix to provide a strong adhesion. This material was developed around the same time as sg iron ductile cast iron back in the 1940s but it is only recently that designers and engineers have started to full utilise its unique mechanical qualities. Compacted graphite iron cgi castings sds scooo042 rev. Us4806157a process for producing compacted graphite iron. Spheroidal graphite is not only found in ductile iron sgi but usually also in cgi, but its characteristics and role in this material is less understood. A common process is when elevated temperatures result in microstructure deterioration, such as the decomposition of pearlite into the equilibrium structure of iron and graphite. The article describes the production of compacted graphite iron castings and the process control that depends on the production volume of components made from compacted graphite iron. The data files were store in ascii format by using commercial. A process for producing compacted graphite cast iron thin walled shaped castings in a high productivity line is provided which comprises. Wear mechanism when machining compacted graphite iron. Compacted graphite iron cgi, also known as vermicular graphite iron, is a metal which is gaining popularity in applications that require either greater strength, or lower weight than cast iron. Pdf production and properties of compacted graphite iron cgi. Foundry production similar to ductile iron, compacted graphite iron is produced by adding magnesium to a desulfurized base iron.
The objective of this work was to create cobased coatings compositionally close to stellite 6 on compacted graphite and gray cast iron substrates with a high power laser 2 kw continuous nd. Compacted graphite iron for diesel engine cylinder blocks. Compacted graphite cg cast iron is also referred to as vermicular graphite, upgraded, or semiductile cast iron ref 1. Compacted graphite iron cgi, also known as vermicular graphite iron gjv, vg, jv or ggv from the german. It could be explained by the alternating growth patterns of compacted graphite. Graphite morphologies in cgi are randomly oriented, elongated and interconnected within eutectic cells as in gray iron, but stubby, bluntedged and have rounded ends and. Compacted graphite iron a material solution for modern diesel engine cylinder blocks and heads he holds a bachelor of engineering metallurgical degree from mcgill university in montreal and master of applied science and doctor of philosophy degrees from the university of toronto. Introduction among the modern varieties of cast iron, cast iron with compacted graphite occupies a special place of growing interest. The choice of cutting tool can dictate how effective shops are able to machine this challenging material. The introduction of modern measurement and control technologies has made cgi a viable material for highvolume series production. Astm a84210 standard specification for compacted graphite. Secondary graphitization is graphite formation that occurs by the transformation of metastable metallic carbides following solidification.
You will be redirected to the full text document in the repository in a few seconds, if not click here. As shown in figure 3, cgi is stable over a range of approximately 0. A395, a536, a476, a874, a897, compacted graphite iron cgi a842 product identification label identifier ductile iron joint restrains. Effect of graphite nodularity on mechanical properties of. His point of view, added to those from rizzo 2001, discloses the enormous. Compacted graphite cast iron cgi is also referred as vermicular graphite. Nov 21, 2012 compacted graphite iron cgi also known as the vermicular graphite cast iron is an alloy with attractive features that is used in the automotive industry ref 14 for brake discs and brake drums, exhaust manifolds, engine heads, and diesel engine blocks, and is traditionally manufactured from gray cast iron. The material compacted graphite iron cgi puts high demands on machining. However, the same mechanical properties of compacted graphite iron cgi. Compacted graphite iron a material solution for modern diesel.
Pdf this research work was carried out to produce compacted graphite iron cgi and to study its mechanical and physical properties. The engine family utilises twin overhead camshafts and multivalves, single or twinturbochargers with an airtoair intercooler, and innovative compacted graphite iron cgi block construction that leads to a low weight of 202 kg 445 lb dry. Its graphite occurs as blunt flakes that are interconnected within each cell. During the last several decades, a multitude of theories have attempted to explain the process of graphite nucleation in lamellar lg and spheroidal sg graphite iron castings. Astm a84211a standard specification for compacted graphite iron castings. Cast and wrought 4140 type steels, and cast and wrought h steels also will be evaluated. Effects of titanium addition on microstructure and mechanical. Shiha a department of mechanical engineering, university of michigan, ann arbor, mi, usa b state key laboratory for manufacturing systems engineering, xi.