Papers by Keyword: Aluminium Matrix Composite

Abstract: Direct hot extrusion is a sustainable technique for recycling aluminium chips into aluminium matrix composite. Reinforcement particles are used to improve the mechanical properties. In this paper, the reinforcing medium of alumina layer that forms on the chip surface were enriched in situ via thermal treatment. Three types of chips were prepared namely; non-treated, treatment of 300 °C for 60 minutes and treatment of 500 °C for 10 minutes. The chips were compacted into chip-based feedstock having a density of 75 %, 85 % and 95 %. The chip-based feedstocks were preheated at 500 °C for 3 hours before extrude. Tensile test performed on the extrudate found that variation in the types of chip and feedstock relative density has affected the ultimate tensile strength. The highest ultimate tensile strength of 256 MPa is obtained from the condition of chip treated at 300 °C for 60 minutes and a feedstock density of 85 %. Elemental analysis on the extrudates reveals that the oxygen content is increased when the extrudates made from heat treated chip. Apart from heat treatment, the oxygen content also affected by the feedstock density.

Abstract: One possible route for producing the fine and homogenous distribution of hard particles in composite microstructure is the mechanochemical processing in which high-energy ball milling promotes the reaction in a mixture of reactive powders. This investigation aims to produce Al – B₄C nanocomposite by reaction between aluminum, boron (III) oxide and graphite powder via a mechanochemical process. The effect of milling time and the ratio the balls to powder on this process were investigated. The face transformation ans structural evaluation were investigated means of X – Ray diffractometry (XRD) and scanning electron microscopy (SEM).

Abstract: This paper aims to understand the influence of sintering temperature on the drilling performance of Al 2219 – SiC_p composite. This type of composite is currently used in aerospace and transportation industries. Drilling is the most frequently employed operation of secondary machining owing to the need for fabrication. This composite is usually subjected to precipitation heat treatment and needs the study of influence of sintering temperature on machining performance. The composite is fabricated through powder metallurgy route. The drilling tests are conducted with PCD drill of 5 mm diameter and 118° point angle. The experiments are conducted under conditions of different spindle speeds of 500, 1000 and 1500 rpm and feed rates of 10, 15 and 20 mm/min. Specific cutting pressure and surface roughness of the hole are considered as performance indicators during the study. Weight fraction of the reinforcement and sintering temperature are found to have significant influence on the drilling performance of the composites.

Abstract: In this paper, the microstructure and mechanical property of the Al-Zn-Mg-Cu aluminum matrix composite reinforced by SiC particles with the contents of 2.5, 4.5, and 6.5wt% through vacuum casting are studied. The homogenization treatment was conducted at 465°C heat insulation for 24h. The purpose of this study is to analyze hot extrusion influence on the microstructure and hardness of the Al-Zn-Mg-Cu aluminum matrix composite. SiCp under pre-processing possesses good wetability with the analysis of Laser Particle Sizer and XRD. Metallurgical microscope, XRD, SEM and EDS is applied to analyze the microstructure of the Al-Zn-Mg-Cu aluminum matrix composite. It has proved that the hot extrusion can effectively improve the homogenization of SiCp and dissolve the second rough phases to reinforce the dispersal of CuAl₂ and MgZn₂ phase. The hardness of Al/SiCp composite rises as the increase of the SiCp content. It is shown that when the SiCp content is above 5%, its hardness obviously reinforced as well as that of the Al/SiCp composite.