Microstructure and Mechanical Properties of AZ91 Rein-Forced with High Volume Fraction of Oriented Short Carbon Fibers

Sabbah Ataya; Mohamed M El-Sayed Seleman; Fahamsyah H Latief; Mohamed M Z Ahmed; Khalil Hajlaoui; Yousef G Y Elshaghoul; Mohamed I A Habba

doi:10.3390/ma15144818

Microstructure and Mechanical Properties of AZ91 Rein-Forced with High Volume Fraction of Oriented Short Carbon Fibers

Materials (Basel). 2022 Jul 10;15(14):4818. doi: 10.3390/ma15144818.

Authors

Sabbah Ataya¹, Mohamed M El-Sayed Seleman², Fahamsyah H Latief^{1

3}, Mohamed M Z Ahmed⁴, Khalil Hajlaoui¹, Yousef G Y Elshaghoul⁵, Mohamed I A Habba⁶

Affiliations

¹ Department of Mechanical Engineering, College of Engineering, Imam Mohammad Ibn Saud Islamic University, Riyadh 11432, Saudi Arabia.
² Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez University, Suez 43512, Egypt.
³ Department of Mechanical Engineering, Faculty of Engineering and Science, Universitas Nasional, Jakarta 12520, Indonesia.
⁴ Mechanical Engineering Department, College of Engineering at Al Kharj, Prince Sattam Bin Abdulaziz University, Al Kharj 16273, Saudi Arabia.
⁵ Mechanical Engineering Department, Faculty of Engineering, Suez University, Suez 43518, Egypt.
⁶ Mechanical Department, Faculty of Technology and Education, Suez University, Suez 43518, Egypt.

Abstract

In this study, AZ91/23 vol.% short carbon fiber composite was produced by a squeeze casting technique using a cylindrical pre-form of treated carbon fibers, in which the fibers are randomly oriented in the horizontal plane. Cylindrical specimens (height = 9 mm and diameter = 6 mm) were machined from the as-cast AZ91 matrix and its composite. The full behavior of the produced composite was studied through the test specimens machined in two directions, namely parallel to the reinforced plane (in the radial direction of the cast cylinder) and normal to the reinforced plane (in the axial direction of the cast composite). The microstructures of the produced composite specimens were investigated using SEM equipped with EDS analysis. Density, hardness, compressive, and wear behavior were also investigated. For comparison, the AZ91 matrix was evaluated as a reference. The microstructure of the produced AZ91 matrix alloy and its composite revealed dense materials without casting defects. Both composite specimens show improvement in hardness, compressive strength, and wear properties over the AZ91 matrix. The compressive and wear properties are more fiber orientation-dependent than the hardness results. The parallel composite specimen depicts the highest compressive properties in terms of yield compressive strength (311 MPa) and ultimate compressive strength (419 MPa), compared to that shown by the AZ91 matrix and the normal composite specimen. This improvement in compressive strength was at the expense of ductility. The parallel composite specimen shows the lowest ductility (R = 3.8%), compared to that given by the normal composite specimen (R = 7.1) and the AZ91 matrix alloy (R = 13.6). The wear testing results showed that at the highest wear load of 5 N, the material weight loss of the parallel composite specimen decreases by 44% and 64% compared to the AZ91 matrix and the normal composite specimen, respectively.

Keywords: AZ91 magnesium alloy; carbon fibers; composite; fiber orientation; mechanical properties; microstructure; squeeze casting.

Grants and funding

RG-21-12-07/Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University