A New Wheel Design for Reducing Weight

2014 ◽  
Vol 794-796 ◽  
pp. 578-583 ◽  
Author(s):  
Frédéric Perrier ◽  
Véronique Bouvier ◽  
Lionel Duperray

Reducing weight is one of the most important challenges in the automotive industry. A wheel design which enables to reduce weight from 13.5 kg to 10 kg is presented. This achievement is possible thanks to the use of a wide variety of technical processes. The disc is manufactured by CobapressTM, a casting/forging process which combines the advantages of a high design freedom, good mechanical properties and the absence of porosities. The alloy used is an A356 aluminum alloy modified with strontium. The rim is made of an AA6082 aluminum alloy which is extruded and flow-formed with a thickness from 3.3 down to 2.2 mm. Finally, the FSW (Friction Stir Welding) allows us to weld the two parts with a cavity to minimize the weight. With this technique the welding of the two different alloys is possible with good mechanical properties, the fracture happens outside of the weld during tensile tests. The final wheels passed bending and radial fatigue tests as well as radial impact tests with success.

2008 ◽  
Vol 141-143 ◽  
pp. 731-736
Author(s):  
H.H. Kim ◽  
S.M. Lee ◽  
C.G. Kang

This study demonstrates fabricating rheological material by EMS system attached vacuum pump, in order to improve mechanical properties of rheoforged products by removing defects such as porosity and oxides arising from rheological forging process. The billet fabricated by EMS in vacuum pressure reduced formation of oxides and porosities of the inner material. The billet fabricated by EMS in vacuum pressure below 56 cm/Hg remarkably reduced porosities, comparing to the EMS in atmospheric pressure.


2008 ◽  
Vol 385-387 ◽  
pp. 849-852 ◽  
Author(s):  
Pasquale Cavaliere ◽  
Francesco W. Panella ◽  
Antonio Squillace

Al-Li alloys are characterized by a strong anisotropy in mechanical properties and microstructure with respect to the rolling direction. Plates of 2198 Al-Li alloy were friction stir welded by employing maximum rotation speed: 1000 rev/min and welding speed of 80 mm/min, both in parallel and orthogonal directions with respect to the rolling one. The joints mechanical properties were evaluated by means of tensile tests at room temperature. In addition, fatigue tests performed with a resonant electro-mechanical testing machine under constant amplitude control up to 250 Hz loading, were conducted in axial control mode with R(σmin/σmax)=0.33, for all the welding and rotating speed conditions. The fatigue crack propagation experiments were performed by employing single edge notched specimens.With the aim to characterize the weld performances, both the microstructure evolution at jointed cross sections, related to the welding variables, and the fractured surfaces were respectively analyzed by means of optical and scanning electron microscopy.


2006 ◽  
Vol 116-117 ◽  
pp. 453-456 ◽  
Author(s):  
Yong Lin Kang ◽  
Yue Xu ◽  
Zhao Hui Wang

In this paper, with a newly self-developed rotating barrel rheomoulding machine(RBRM), microstructures and mechanical properties of rheo-die casting A356 alloy were studied. In order to clearly show the characteristic of rheo-die casting, liquid die casting and semi-solid casting were done too. The experimental results showed that microstructures of rheo-die casting were composed of solid grains, which were finer and rounder, and had fewer pores. In the three technologies, integrated mechanical properties of semi-solid rheo-die casting were the best.


2011 ◽  
Vol 409 ◽  
pp. 281-286
Author(s):  
Yutaka Matsuda ◽  
Goroh Itoh ◽  
Yoshinobu Motohashi

Friction stir processing (FSP) is a method for controlling the microstructure that has been proposed by applying friction stir welding, FSW. In this study, microstructure and mechanical properties of a 7075 aluminum alloy subjected to multi-pass FSP, MP-FSP, are assessed to obtain fundamental knowledge for improving the plasticity of aluminum alloys. The MP-FSP has been applied to 7075 alloy plates with T6 and O tempers, and microstructural characterization has been made by means of optical and scanning electron microscopies together with EDX and EBSD analyses, while mechanical properties were measured by means of micro hardness and tensile tests at room and high temperatures. From microstructural observation, a new zone, PBZ, has been discovered between stir zones, SZs. The PBZ is composed of two types of (fine and coarse) grains, where the coarse grain contains many sub-grains. Hardness in PBZ is intermediate between that in BM and SZ both in T6 and O specimens; hardness generally decreases and increases in T6 and O specimens, respectively, by MP-FSP. In accord to the hardness change, strength at room temperature is decreased by MP-FSP in T6 specimen, and increased in O specimen. Elongation at 773K is increased both in T6 and O specimens because of superplastic deformation. However, local elongation is smaller in PBZ than in SZ, which can be attributed to the microstructural change by the deformation: grain shape remains equiaxed in SZ while it becomes elongated in the tensile direction in PBZ.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Abou Bakr Elshalakany ◽  
T. A. Osman ◽  
A. Khattab ◽  
B. Azzam ◽  
M. Zaki

A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs) were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloy matrix and the MWCNTs were examined by using an optical microscopy (OM) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis (EDX). This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt%) of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5 wt% MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs.


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