Manufacturing Processes and Engineering Materials Used in Automotive Engine Blocks by Hieu Nguyen School of Engineering Grand Valley State University Term Paper EGR250 Materials Science and Engineering Section B Instructor Dr P N Anyalebechi April 8 2005 Manufacturing Processes and Engineering Materials Used in Automotive Engine Blocks Abstract Until recently cast iron and aluminum alloys have been the preferential materials used to manufacture most diesel and conventional gasoline powered engine blocks However with a greater emphasis on increasing the efficiency of the engine via weight reduction manufacturers have began to look for alternative alloys that are lighter than cast iron and aluminum alloys while retaining the necessary strength to withstand the forces of an engine As of late new manufacturing processes have been developed that have engendered two new alloys suitable for use in an engine block magnesium alloy AMC SC1 and compacted graphite cast iron CGI In this paper the functional requirements of the engine block the processes used to manufacture the part and the mechanical properties of the alloys will be discussed 1 Introduction The first successfully working internal combustion engine used in an automobile was built by Siegfried Marcus in approximately 1864 1 It was an upright single cylinder twostroke petroleum fueled engine that also utilized a carburetor to deliver fuel to the engine The engine was placed on a cart with four wheels and successfully ran under its own power Not only has Marcus produced the first engine that is the direct predecessor to today s engines he had also built the first automobile in history some 20 years before Gottlieb Daimler s automobile Today s engines are an integral component of an automobile that are built in a number of configurations and are considerably more complex than early automotive engines Technological innovations such as electronic fuel injection drive by wire i e computercontrolled throttles and cylinder deactivation have made engines more efficient and powerful The use of lighter and stronger engineering materials to manufacture various components of the engine has also had an impact it has allowed engineers to increase the power to weight of the engine and thus the automobile 2 Common components found in an engine include pistons camshafts timing chains rocker arms and other various parts When fully stripped of all components the core of the engine can be seen the cylinder block The cylinder block popularly known as the engine block is the strongest component of an engine that provides much of the housing for the hundreds of parts found in a modern engine Since it is also a relatively large component it constitutes 20 25 of the total weight of an engine 2 Thus there is much interest in reducing the block s weight Many early engine blocks were manufactured from cast iron alloys primarily due to its high strength and low cost But as engine designs became more complicated the weight of the engine and the vehicle had increased Consequently the desire among manufacturers to use lighter alloys that were as strong as cast irons arose One such material that was being used as a substitute was aluminum alloys Used sparingly in the 1930 s due to problems with durability 3 aluminum alloy use in engine blocks increased during the 1960 s and 1970 s as a way to increase fuel efficiency and performance Together these two metals were used exclusively to fabricate engine blocks As of late however a new material process has made a magnesium alloy suitable for use in engines The alloy called AMC SC1 weighs less than both cast iron and aluminum alloys and represents new possibilities in engine manufacturing A new manufacturing process have made compacted graphite cast iron CGI a viable alternative to gray cast iron for the manufacture of diesel engine blocks Like magnesium alloys this material offers a higher strength and lower weight than gray cast iron In this paper materials used to manufacture engine blocks for passenger vehicles will be discussed The discussion of the component its functional requirements and the materials used to manufacture the part are included The mechanical properties of the individual alloys will be incorporated as well as the manufacturing processes used to fabricate the component 2 Description of the Product 2 1 What is an engine block An engine block is the core of the engine which houses nearly all of the components required for the engine to function properly The block is typically arranged in a V inline or 3 horizontally opposed also referred to as flat configuration and the number of cylinders range from either 3 to as much as 16 Figure 1 shows engine blocks with V inline and horizontallyopposed configurations Figure 1 Cylinder blocks in V inline and horizontally opposed configurations 4 6 2 2 Functional Requirements of a Cylinder Block Because engine blocks are a critical component of an engine it must satisfy a number of functional requirements These requirements include lasting the life of the vehicle housing internal moving parts and fluids ease of service and maintenance and withstand pressures created by the combustion process 2 3 Required Material Properties In order for an engine block to meet the functional requirements listed above the engineering material s used to manufacture the product must possess high strength modulus of elasticity abrasion resistance and corrosion resistance High strength is a particular concern in diesel engines since compression ratios are normally 17 0 1 or higher compared to about 10 0 1 for conventional engines The material should also have a low density thermal expansion to resist expanding under high operating temperatures and thermal conductivity to prevent failure under high temperatures Good machinability and castability of the metal alloy are also important factors in selecting the proper material as the harder it is to machine the product the higher the costs of manufacturing In addition to the previously mentioned properties the alloys must possess good vibration damping to absorb the shuddering of the moving parts 4 2 4 Metals Used in the Manufacture of the Cylinder Blocks Based on the functional requirements of the cylinder block and the material properties required to meet the functional requirements industries have used cast iron and aluminum alloys to manufacture the blocks Cast iron alloys are used because of the combination of good mechanical