Vol.:(0123456789) 1 3 Metals and Materials International https://doi.org/10.1007/s12540-019-00391-3 Development of Functionally Graded Tubes Based on Pure Al/Al 2 O 3 Metal Matrix Composites Manufactured by Centrifugal Casting for Automotive Applications Bassiouny I. Saleh 1,2  · Mahmoud H. Ahmed 1 Received: 17 April 2019 / Accepted: 21 July 2019 © The Korean Institute of Metals and Materials 2019 Abstract This paper studies the infuence of main parameters on the mechanical properties and wear behaviour of functionally graded materials pure Aluminum reinforced by various weight fractions of aluminium oxide (Al 2 O 3 ). A Functionally graded (FG) pure aluminium/Al 2 O 3 tube was processed by horizontal centrifugal casting method. The hollow tube dimen- sions 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 diferent 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 Al 2 O 3 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 appli- cations lies in engineering parts and structures that have location specifc property requirements and per formance 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 heterogene- ous composites where the composition and/or microstruc- ture of the material is varied locally in order to regulate the physical and mechanical features of a component at a certain place. FGMs originated in 1984 frst 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 specifc engi- neering applications such as automotive, aerospace, elec- tronics, power generation, and bioengineering [4]. Because it has high temperature resistance, thermal characteristics, increased bonding and fracture toughness on the transition between metal matrix and reinforcement ceramic. The gra- dient transition zone in density, modulus of elasticity, grain size, or distribution of particles through an interface in the matrix of two or more materials can easily decrease thermal stresses, stress concentration, and design ability for various complex environments [5]. Most FGM study consists of multi-phase materials with the continuous changes in the properties leading to the for- mation of a controlled, non-uniform microstructure. The * Bassiouny I. Saleh bassiouny.saleh@hhu.edu.cn 1 Production Engineering Department, Alexandria University, Alexandria 21544, Egypt 2 College of Mechanics and Materials, Hohai University, Nanjing 211100, China