Design of magnetic aluminium (AA356) composites (AMCs) reinforced with nano Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e, and recycled nickel: Copper particles

New classes of aluminium matrix composites (AMCs – 356) were designed by three different manufacturing techniques; only sintering, through combined method called here after “Sinter + Forging” and/or “sinter + thixoforming”. Main reinforcement was magnetic iron oxide, Fe3O4(10, 20 and 30 wt %) and two recycled reinforcements, nickel, Ni and pure electrolytic copper, Cu, given by French Aeronautical Society were also used and preceded under the constant process parameters such as hot compaction, sinter-forging, sintering time, Forging temperature and Force, etc. As auxiliary element, hybrid graphene nano-platelets, GNPs, was added in the structure. Microstructural analyses (by using SEM), magnetic, mechanical and physical properties of the composites were compared with three different manufacturing processes. Static compression tests, Micro hardness tests, measurement of magnetic permeability and also electrical conductivity, have shown that the mechanical and physical properties of these composites can be improved with the optimization of process parameters. In the present work, an alternative and a low cost manufacturing process were proposed for these composites

Design of Intermetallic Mg (Recycled Ti-Al) Based Composites Through Semi Powder Metallurgy Method

International audienc

Web-post buckling resistance calculation of perforated high-strength steel beams with elliptically-based web openings for EC3

There has been an increase in the use of high-strength steel, as it provides lightweight structural members by satisfying environmental and economic issues. This paper aims to implement high-strength steels in the web-post buckling resistance equation, which was based on the truss model according to EUROCODE 3, presented previously by the authors. For this task, a finite element model is developed and employing geometrically and materially nonlinear analysis with imperfections. A parametric study is carried out, considering the key geometric parameters that influence the web-post buckling resistance. Three high-strength steel grades are studied (S460, S690 and S960) and in total, 13,500 finite element models are processed. A new factor for adapting high-strength steels to the equation proposed previously was presented. The statistical parameters calculated, via the ratio between the numerical and analytical models, considering the regression, mean, standard deviation and variance, were 0.9817, 0.985, 8.29% and 0.69%, respectively. In conclusion, a reliability analysis was presented based on Annex D EN 1990 (2002)

Manufacturing of recycled aluminum matrix composites reinforced of TiC/MoS2/Al2O3 fiber through combined method: Sintered + forging

Aluminum based hybrid composites were produced from recycled AA7075 chips with the addition of TiC (d ≤ 3–5 micron), MoS2 and Al2O3 fiber. In the two groups of composites produced, the content of MoS2 and Al2O3 were fixed as 2 wt % and 3 wt % respectively, whereas TiC content was at two levels (5–10%). The combined method of powder metallurgy route, sintering followed by forging, was used to manufacture these composites. These composites are targeted for aeronautical and automotive industries for components subjected to static as well as cyclic and dynamic loading. In addition to mechanical properties, machinability of these composites is of importance hence, MoS2 was included in the formulation. Micro hardness, 3 point bending, low velocity impact and nanoindentation (creep and wear) tests were performed on samples manufactured by just sintering and sintering followed by forging. The results showed that, in generals, the samples that were forged after sintering yielded better properties. The microstructure analyses (matrix/interface) have been carried out by Scanning Electron Microscope (SEM)

Recycling of aluminium-431 by high energy milling reinforced with TiC-Mo-Cu for new composites in connection applications

In this work, an alternative aluminium matrix composite (AMCs) was designed from the recycled chips of the aluminium, Alumix 431 given by Brazilian aeronautic company, through combined method of powder metallurgy followed by Sintering + Forging. We aimed for the application for the connection pieces to transfer motion mainly used in automotive and aeronautical area as an alternative replacement for conventional alloys used in this area. First of all, A typical matrix was developed from recycled aluminium (AA 431) chips by high energy milling in a planetary ball mill with an inert argon atmosphere to prevent oxidation of the powders and this matrix was reinforced basically with TiC (5 wt % and 10 wt %) and molybdenum and copper (Mo 4 wt %, Cu 4 wt %) as a secondary reinforcements respectively. Mechanical and physical properties were evaluated through micro-hardness, static compression and 3 point bending (PB) tests and impact-drop weight tests were carried out. The microstructure analyses have been carried out by Scanning Electron Microscope (SEM)

Alternative Composite Design from recycled aluminium (AA7075) chips for knuckle applications-II

In this work, an alternative aluminium matrix composite (AMCs) was designed from the recycled chips of the aluminium series of AA7075 (90 wt %) and Al-Zn-Mg-Si-Ni (10 wt %) given by French aeronautic company to prepare a typical matrix after that we have designed a composite through combined method of powder metallurgy followed by Sintering + Forging. Basically, B2O3 (4 wt %, 8 wt %), TiC (5 wt %), fine Al2O3 Fibre (5 wt %), Zn (4 wt %) and Nb2Al (4 wt %) were added as the main reinforcements. To increase wettability of the reinforcements, we doped them through a thermomechanical treatment. The main idea of this research is to propose an alternative low cost composite for the application in a mechanism to transfer motion for the connection links, for example; between the two railways wagons etc. and also some connecting link in aeronautical pieces as an alternative replacement for conventional alloys used in this area. Mechanical properties, static compression 3-Point Bending (3PB) and dynamic drop weight tests and also micro-hardness results of these composites have been carried out. The microstructure analyses were evaluated by Scanning Electron Microscope (SEM)

Alternative Composite Design from Recycled Aluminum Chips for Mechanical Pin-Joint (Knuckle) Applications

International audienc

Manufacturing of copper based composites reinforced with ceramics and hard intermetallics for applications of electric repair parts

In the present work, a recycled copper based composites reinforced with ceramic as an alternative replacement for the application of electric motor repair parts with the use of novel processing techniques. A practical solution was proposed as cost effective economic manufacturing of the composites for this type of applications. Copper based composite design (Cu-Al-Nb2Al) was based on the ceramic reinforcements such as titanium carbide (TiC) in different percentages and niobium aluminate intermetallics (Nb2Al). Because TiC and Nb2Al make a good combination of thermal and electrical conductivities, microstructural stability and strength retention at elevated temperatures, etc. These reinforcements increase considerably wear resistance of the composites for electrical contact applications. Otherwise, certain percentage of fresh scrap aluminium powder, the mixture of AA1050 (80 wt% + AA7075 (20 wt %) chips were used to create an exothermic combustion reaction in the process for helping diffusion bonding process of the ceramics to the copper matrix. At the first stage of the present work a preliminary study has been carried out for developing a cost effect and high wear resistant electrical brushes for aeronautical applications. Microstructural and wear analyses have been carried out to optimize the process conditions for a practical tool that will be used for final industrial applications. Three basic compositions were prepared depending on the percentage of TiC. The microstructure and damage analyses have been carried out by Scanning Electron Microscope (SEM)