The increasing need for materials with light weight, high resistance to corrosion and wear, toughness and strength, machinability, high thermal capacity etc. for various applications is unending. This demand has continued to stretch the exploitation and manipulation of various functionally graded materials (FGMs) and their production methods. This study explores one of the FGM production processes called the centrifugal casting technique (CCT). The centrifugal casting process has several potential advantages over traditional casting methods. This study provides information regarding the basic functionally graded production methods and their applications and also discusses categories of CCT, evolution and process parameters.

No abstract

This study focuses on primary impurities, called intermetallics, in the microstructure of Al-SiX alloys, their formation, effects and treatments to eliminate or ameliorate their deleterious effects. Intermetallic compounds are usually formed when alloying elements, such as Fe, Cu, Mn, Mg and Sr. are added to Al-Si based alloys. These elements are depicted by X in the alloys formation expression. The chapter noted that the most common intermetallics are iron (Fe) based, and several of these Fe-phases, including the most harmful Fe-phase, β-Al 5 SiFe, are listed and discussed. Fe-phase intermetallics are deleterious to the mechanical properties of Al-alloys; however, addition of <0.7% Fe helps prevent soldering in die casting mould. The effects of Fe-phase and other intermetallics formed by Cu, Mg and Mn were examined. Further, some techniques of eliminating or mitigating the negative influences of intermetallics were discussed.

This chapter discusses the concepts, casting techniques and applications of functionally graded materials metal matrix composites (FGMMCs). Considerations were given to bulk functionally graded aluminium matrix composites (FGAACs) production processes. Liquid-metal forging processes of FGAACs fabrication, such as infiltration process, squeeze casting, friction casting or compocasting, stir, and centrifugal casting were discussed. The chapter provides basic concepts of the processes and overview of their processing parameters, such as mould rotational speed; reinforcement particles size and volume; degassing method; melting and pouring temperatures; pressure; and stirrer. The study notes that functionally graded materials (FGMs) are commonly used in automotive, aircraft, aviation, chemical, medical, engineering, renewable energy, nuclear energy, and optics electronics industries.

No abstract

This paper discusses the main Functionally Graded Materials (FGMs) and their bulk fabrication techniques, their development, principles and applications. The fabrication processes considered include powder metallurgy (PM), sintering, squeeze casting, infiltration process, compocasting, centrifugal casting, stir casting, material prototyping. The paper provides an overview of the FGM processing parameters including reinforcement particles size and volume %, temperature, pressure (for PM), and stirrer and mould rotational speeds (for stir and centrifugal casting processes respectively). The paper notes that the FGMs are widely used in the following sectors: automotive, medical, aerospace, aviation, nuclear energy, renewable energy, chemical, engineering, optics electronics etc.

No abstract

The fabrication of functionally graded aluminum metal matrix composite with varying properties using a centrifugal casting technique was carried out using silicon carbide particles (SiCp) of an average particle size of 15 µm as reinforcement. The effect of the SiCp reinforcements at different weight-percent on the hardness and tensile properties of A356 aluminum alloy was studied. The effect of particle size of the SiC reinforcement on the properties of the aluminum alloy was also investigated. It was observed that the hardness of the fabricated composite gradually increased from the center of the fabricated materials to their ends while the overall hardness of the samples increased as the weight-percent of the reinforcement addition increased. This observation also held true for the tensile properties of the materials. The property variations observed are attributed to the dispersion of the reinforcement within the aluminum matrix before solidification under centrifugal force action.