• PDF / 2,399,580 Bytes
• 11 Pages / 595.276 x 790.866 pts Page_size
• 16 Downloads / 262 Views

DOWNLOAD

REPORT

---

Development of Functionally Graded Tubes Based on Pure Al/Al2O3 Metal Matrix Composites Manufactured by Centrifugal Casting for Automotive Applications Bassiouny I. Saleh1,2 · Mahmoud H. Ahmed1 Received: 17 April 2019 / Accepted: 21 July 2019 © The Korean Institute of Metals and Materials 2019

Abstract This paper studies the influence of main parameters on the mechanical properties and wear behaviour of functionally graded materials pure Aluminum reinforced by various weight fractions of aluminium oxide (­ Al2O3). A Functionally graded (FG) pure aluminium/Al2O3 tube was processed by horizontal centrifugal casting method. The hollow tube dimensions are 230 mm outer diameter x 12 mm thickness x 180 mm length. The properties of these FG tubes were compared with unreinforced alloy. Hardness and tensile results in the radial direction showed that the hardness and tensile in accordance with the gradient microstructure was improved from inner zone to outer zone. Wear tests were carried out for different test duration at a constant sliding speed of 8 m/s and loads applied are 14, 24 and 40 N. In all test conditions the wear rate in the outer layer was minimum compared to other layers. In the surface analysis, scanning electron microscope indicated the presence of delamination, wear debris and cracks. FG tubes reinforced by A ­ l2O3 particles have increased mechanical properties and wear resistance compared to its unreinforced alloy (matrix alloy) and is suitable for use in automobile and transport applications. Keywords  Wear · Functionally graded material (FGM) · Centrifugal casting · Metal matrix composites (MMC) · Pure aluminium · Aluminium oxide particles · Wear loss

1 Introduction The demand for a variety of modern technological applications lies in engineering parts and structures that have location specific property requirements and performance under working conditions. A progressive transition to the properties motivates changes to the functions of a given location in order to meet the needs [1]. These tailored materials are functionally graded materials (FGMs). FGMs are relatively a new class of advanced heterogeneous composites where the composition and/or microstructure of the material is varied locally in order to regulate the physical and mechanical features of a component at * Bassiouny I. Saleh [email protected] 1



Production Engineering Department, Alexandria University, Alexandria 21544, Egypt



College of Mechanics and Materials, Hohai University, Nanjing 211100, China

2

a certain place. FGMs originated in 1984 first in Japan during the design of a space shuttle [2]. The phenomena of gradient structures, like bamboo, teeth, bone, wood, etc. and of certain conventional engineering materials are prevalent in nature [3]. Functionally graded materials (FGM) developments remain in its early stages and scope for developing a variety of real FGM for thermal protection systems for specific engineering applications such as automotive, aerospace, electronics, power generation, and bioengineering [