Thermal and Mechanical Analyses of Dry Clutch Disk made of Functionally Graded Material.

This paper presents an innovative utility of Functionally Graded Aluminum Matrix Composite (FGAMC) with Silicon Carbide as a friction material in clutches since having an acceptable friction coefficient and high wear resistance. FGAMC’s properties were calculated using rule-of-mixture and power law, represented by layered geometry. FGAMC’s behavior is examined considering statics, dynamics, thermal and wear. Analyses were done using Finite Element method, by ANSYS. Results are discussed by comparing FGAMC’s clutch to Aluminum matrix composite with 20% of Silicon Carbide clutch and E-glass clutch. Clutches design based on the common size and working conditions of clutches in mid-size and heavy automobiles. Most analyses revels FGAMC’s clutch has higher strain than AMC’s clutch with less deformation in thickness direction and less stresses. FGAMC’s clutch has higher mass leading to lower first natural frequency but with low resulted deformations. Transient analyses showed 10 times fewer maximum deformations for FGAMC’s clutch than AMC and E-glass with lower strains and higher stress but in much less area for FGAMC’s clutch. Wear which indicates working life of a clutch, have been studied using Archard Wear Equation in ANSYS, FGAMC’s clutch has 10 times lower wear with much less affected area compared to AMC and E-glass. Thermal analysis results of the three clutches are close to each other with 0.07 watts between FGAMC’s and AMC’s clutches, and 0.03 watts between FGAMC’s and E-Glass’s clutches.

Forming Process and Simulation Analysis of Helical Carbon Fiber Reinforced Aluminum Matrix Composite

In order to promote the industrialization of the large deformation technology of carbon fiber composites, this paper studies a new method of forming of helical carbon fiber reinforced aluminum matrix composite. The purpose is to solve the problem of large deformation of carbon fiber with low elongation and metal matrix with high elongation. By introducing carbon fiber with helical space structure into the aluminum matrix, the helical carbon fiber reinforced aluminum matrix composites were prepared and the subsequent drawing deformation was carried out. Here we systematically studied the large plastic deformation behavior of helical carbon fiber reinforced aluminum matrix composite via a combination of numerical simulations and experiments, and analyzed the deformation law and stress of helical carbon fiber in the deformation process. We found that the plastic deformation of the composite causes local stress concentration around the helical carbon fiber, and the helical carbon fiber will move synchronously with the aluminum matrix during the deformation, and receive the pressure from the aluminum matrix. Second, the best process parameters obtained from the simulation, that is, the drawing die angle α = 7°, when five-pass drawing experiments were carried out, the total deformation reached 58%, and the average elongation of a single pass was 18.9%. The experimental show carbon fiber reinforced aluminum matrix composite with helical space structure can achieve large deformation and high strength. The experimental and simulation are in general agreement, which verifies the correctness of the carbon fiber helical structure model.

Recent Progress in Hybrid Aluminum Composite: Manufacturing and Application

Due to their excellent properties, the requirement for materials with higher characteristics has transformed primary alloy into composite materials. Composites are particularly essential for various applications in numerous engineering purposes because of their superior mechanical, physical, and machining qualities. Compared to traditional materials, aluminum composite has various advantages and superior characteristics. To reduce production costs and obtain the desired properties, the researchers developed a hybrid aluminum matrix composite (HAMC), an AMC with two or more types of reinforcement. Further studies were conducted to improve the qualities and manufacturing processes of composites to improve their properties. Various methods are available to HAMC manufacturing, and different manufacturing methods result in different characteristics of HAMC composites, viewed from physical properties, mechanical properties, and production cost. In addition, differences in the type, size, and amount of reinforcement produce various hybrid composite properties, especially in the physical properties, mechanical properties, and tribological behavior of HAMC. This work presents a comprehensive review of recent progress in HAMC study with various reinforcement particles, manufacturing techniques, physical, mechanical, and tribological properties of HAMC. On the other side, this work provides discussion for application, challenges, and future work conducted for HAMC development.

ADDITION OF MAGNESIUM (Mg) WITH ALUMINA (AL2O3) REINFORCER IN ALUMINUM MATERIAL COMPOSITES ON THE MECHANICAL PROPERTIES AND MICRO STRUCTURES

Aluminum is a widely used and applied material in daily life or in the industrial and automotive world. In order to improve the performance and properties of the application to be used, it needed an alloying element to improve the mechanical properties of the aluminum. Aluminum Matrix Composite (AMC) or better known as aluminum matrix composite is one type of material that has great potential to be developed, due to its good combination and properties such as high strength and hardness, low density, low density, capable of good machining, and its basic ingredients are easily found on the market and cheaper than other materials. This research was conducted using the stir casting process to be able to mix all the compositions contained in aluminum matrix composites and to help the distribution of alumina reinforcing particles (Al2O3) and aluminum matrices be evenly distributed. The parameters used in this casting process are varying the volume fraction of the Al2O3 amplifier by 0.5%; 1.5% and 2.5% plus the magnesium content remains 0.9%. The results showed that the addition of Al2O3 can increase the value of hardness and reduce the value of tensile strength. The highest hardness value was 75.3 HRB at the addition of Al2O3 by 2.5% and the lowest tensile strength value was 7.17 Kgf / mm2 with the percentage of Al2O3 addition of 0.5%.

Manufacturing and Performance of Carbon Short Fiber Reinforced Composite Using Various Aluminum Matrix

A new fabrication process without preform manufacturing has been developed for carbon short fiber (CSF) reinforced various aluminum matrix composites. And their mechanical and thermal properties were evaluated. Electroless Ni plating was conducted on the CSF for improving wettability between the carbon fiber (CF) and aluminum. It was confirmed that pores in Ni plated CSF/Al and Al alloy matrix composites prepared by applied pressure, 0.8 MPa, had some imperfect infiltration regions between the CF/CF and CF/matrix in all composites. However, pores size in the region between the CF/CF and CF/matrix to use the A336 matrix was about 1 µm. This size is smaller than that of other aluminum-based composites. Vickers hardness of Ni plated CSF/A1070, A356 alloy, and A336 alloy composites were higher as compared to matrix. However, the A1070 pure aluminum matrix composite had the highest hardness improvement. The Ultimate tensile strength of the A1070 and A356 aluminum matrix composite was increased due to carbon fiber compared to only aluminum, but the Ultimate tensile strength of the A336 aluminum matrix composite was rather lowered due to the highest content of Si precipitate and large size of Al3Ni compounds. The Thermal Conductivity of Ni plated CSF/A1070 composite has the highest value (167.1 W·m−1·K−1) as compared to composites.

Regeneration of Aluminum Matrix Composite Reinforced by SiCp and GCsf Using Gas Tungsten Arc Welding Technology

The main motivation behind the presented research was the regeneration of the damaged surface of composite materials. The testing of melting and pad welding of the composite surface by Gas Tungsten Arc Welding (GTAW) with alternating current (AC) were carried out. The material of investigation was an AlSi12/SiCp + GCsf hybrid composite made by a centrifugal casting process. The composite was reinforced with 5 wt.% of silicon carbide particles and 5 wt.% of glassy carbon spheres. The composites were investigated in tribological tests. It was found that there was a possibility for modification or regeneration of the surface with pad welding technology. Recommended for the repairs was the pad welding method with filler metal with a chemical composition similar to the aluminum matrix composite (ISO 18273 S Al4047A (AlSi12 [A])). The surface of the pad welding was characterized by the correct structure with visible SiCp. No gases or pores were observed in the pad welding; this was due to a better homogeneity of the silicon carbide (SiCp) distribution in the composite and better filling spaces between liquid metal particles in comparison to the base material. Based on the tribological tests, it was found that the lowest wear was observed for the composite surface after pad welding. This was related to the small number of reinforcing particles and their agreeable bonding with the matrix. The plastic deformation of the Al matrix and scratching by worn particles were a dominant wear mechanism of the surface.

Wear Dry Behavior of the Al-6061-Al2O3 Composite Synthesized by Mechanical Alloying

The present research deals with the comparative wear behavior of a mechanically milled Al-6061 alloy and the same alloy reinforced with 5 wt.% of Al2O3 nanoparticles (Al-6061-Al2O3) under different dry sliding conditions. For this purpose, an aluminum-silicon-based material was synthesized by high-energy mechanical alloying, cold consolidated, and sintered under pressureless and vacuum conditions. The mechanical behavior was evaluated by sliding wear and microhardness tests. The structural characterization was carried out by X-ray diffraction and scanning electron microscopy. Results showed a clear wear resistance improvement in the aluminum matrix composite (Al-6061-Al2O3) in comparison with the Al-6061 alloy since nanoparticles act as a third hard body against wear. This behavior is attributed to the significant increment in hardness on the reinforced material, whose strengthening mechanisms mainly lie in a nanometric size and homogeneous dispersion of particles offering an effective load transfer from the matrix to the reinforcement. Discussion of the wear performance was in terms of a protective thin film oxide formation, where protective behavior decreases as a function of the sliding speed.

Aluminum Composite Materials Providing Extended Service Life

Hardness and tribotechnical characteristics were investigated under conditions of dry sliding friction on steel obtained by liquid-phase mixing of Aluminum-Matrix Composite (AMC) materials based on aluminum alloys AK12, D16, V124, AL9, AL25, reinforced with silicon carbide SiC particles with a size of 28 μm with a content of 5, 10 or 15% by volume. AMC performed better than matrix alloys and the commonly used antifriction aluminum alloy AOM 2-1. The dry friction coefficient was 1.5-3 times lower on average, and the volumetric wear rate was 5-9 times lower. An increase in the content of SiC particles in the composite from 5 to 20 vol.%. As a rule, leads to an improvement in the tribotechnical characteristics. The composites obtained have shown a sufficiently high operational suitability for work in friction units with steels both in dry friction and in friction with lubrication.