scholarly journals Microstructural and mechanical behavior of Al 6061/SiC-Al2O3 composites processed through friction stir processing

Author(s):  
Mohana Rao Chanamallu ◽  
K. Meera Saheb

Metal Matrix Composite (MMC) reinforced in friction stir processing (FSP) has increased insights that can affectively attain the desired mechanical properties for the manufactured samples. The favorable conditions of carbides are considered for reinforcing the SiC particles into the Aluminum 6061. The methodology of fabricating Aluminum 6061 comprises of three materials, Al 6061-SiC-Al2O3. The experimental evaluation of the composite Aluminum 6061-SiC-Al2O3 includes the influence of process parameters on microhardness, tensile strength, and microstructure. As a result of the reinforcement of nanoparticles processed in FSP, the properties of composite material increased satisfactorily. The sample S3 observed to be having a maximum tensile strength of 185 MPa. The larger, the better condition is adopted to analyze the tensile strength of the fabricated samples. The optimum condition for maximum tensile strength was found at 900 RPM, 15 mm/min, and composition 3. The hardness profiles at different zones of friction stir processing (FSP), viz., Heat Affected Zone (HAZ), Thermo Mechanical Affected Zone (TMAZ), Nugget Zone (NZ) were examined. The characterization techniques deployed were optical microscope (OM), and scanning electron microscope (SEM) studies for microstructural behavior. The result shows that the reinforcements were tightly embedded into the base material surface. The spherical grains are formed in the reinforcement region.

2020 ◽  
Vol 1002 ◽  
pp. 140-150
Author(s):  
Ali H. Al-Helli ◽  
Ahmed R. Alhamaoy ◽  
Ayad Murad Takhakh

Friction Stir Processing (FSP) technology was wielded to output the Al7075/ Al2O3 surface composite. The effects parameters of processing method on particle distribution have been studied. The microstructure and mechanical characteristics of the samples were examined using the optical microscope, SEM and hardness examination. Acquired consequences, showed that Al2O3 particles were in a good interior distribution inside the basement. This technique produced excellent bonding between the surface composite and the base material. On other hand the surface hardness was increased about 25% as compared with the substrate. In addition, grain matrix refinement and enhanced particle distribution were obtained after each FSP pass. Also the dispersion of Al2O3 particles in the stirred area became more homogeneous and the average hardness improved by increasing the number of passes.


2017 ◽  
Vol 67 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Dakarapu Rao Santha ◽  
Nallu Ramanaiah

Abstract Friction stir processing (FSP) is solid state novel technique developed to refine microstructure and to improve the mechanical properties and be used to fabricate the aluminium alloy matrix composites. An attempt is made to fabricate AA6061/TiB2 aluminium alloy composite (AMCs) and the influence of process parameters like rotational speed, transverse feed, axial load and percentage reinforcement on microstructure and mechanical properties were studied. The microstructural observations are carried out and revealed that the reinforcement particles (TiB2) were uniformly dispersed in the nugget zone. The Tensile strength and Hardness of composites were evaluated. It was observed that tensile strength, and hardness were increased with increased the rotational speed and percentage reinforcement of particles. The process parameters were optimized using Taguchi analysis (Single Variable) and Grey analysis (Multi Variable). The most influential parameter was rotational speed in single variable method and multi variable optimization method. The ANOVA also done to know the percentage contribution of each parameter.


2019 ◽  
Vol 8 (2) ◽  
pp. 3979-3983 ◽  

Friction stir processing is a modified form of friction stir welding process which is introduced to prepare the surface composites or to repair the defects in the surface to enhance the mechanical properties. The process is a green and environmental friendly process, where the required heat is produced by frictional action. In the present work, Surface composites were prepared using Al 5052 as base material and Al2O3 as reinforcement particles. Parameters such as number of passes, spindle speed, feed rate and tool pin profile were taken in three different levels. Six tools were made, three tools with 3:1 and remaining three with 4:1 D to d ratio. Totally 18 experiments were conducted with two group of tools. The results were analyzed to study the influence of above mentioned parameters on mechanical properties like tensile strength, hardness. The results were compared for different D/d ratios. The experimental results revealed that 3:1 D/d ratio tools were given better results than 4:1.Tool with square pin profile given better hardness and strength than the other profiles. This is because of the pulsating effect of the square pin profile. The other parameters have directly proportional relationship up to certain level, after which further increase of parameters reduces the tensile strength and hardness.


2019 ◽  
Vol 13 (4) ◽  
pp. 5804-5817
Author(s):  
Ibrahim Sabry

It is expected that the demand for Metal Matrix Composite (MMCs) will increase in these applications in the aerospace and automotive industries sectors, strengthened AMC has different advantages over monolithic aluminium alloy as it has characteristics between matrix metal and reinforcement particles.  However, adequate joining technique, which is important for structural materials, has not been established for (MMCs) yet. Conventional fusion welding is difficult because of the irregular redistribution or reinforcement particles.  Also, the reaction between reinforcement particles and aluminium matrix as weld defects such as porosity in the fusion zone make fusion welding more difficult. The aim of this work was to show friction stir welding (FSW) feasibility for entering Al 6061/5 to Al 6061/18 wt. % SiCp composites has been produced by using stir casting technique. SiCp is added as reinforcement in to Aluminium alloy (Al 6061) for preparing metal matrix composite. This method is less expensive and very effective. Different rotational speeds,1000 and 1800 rpm and traverse speed 10 mm \ min was examined. Specimen composite plates having thick 10 mm were FS welded successfully. A high-speed steel (HSS) cylindrical instrument with conical pin form was used for FSW. The outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt. %) was 195 MPa at rotation speed 1800 rpm, the outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt.%) was 165 MPa at rotation speed 1000 rpm, that was very near to the composite matrix as-cast strength. The research of microstructure showed the reason for increased joint strength and microhardness. The microstructural study showed the reason (4 %) for higher joint strength and microhardness.  due to Significant   of SiCp close to the boundary of the dynamically recrystallized and thermo mechanically affected zone (TMAZ) was observed through rotation speed 1800 rpm. The friction stir welded ultimate tensile strength Decreases as the volume fraction increases of SiCp (18 wt.%).


2011 ◽  
Vol 189-193 ◽  
pp. 3266-3269 ◽  
Author(s):  
Yu Hua Chen ◽  
Peng Wei ◽  
Quan Ni ◽  
Li Ming Ke

Titanium alloy TC1 and Aluminum alloy LF6 were jointed by friction stir welding (FSW), and the influence of process parameters on formation of weld surface, cross-section morphology and tensile strength were studied. The results show that, Titanium and Aluminum dissimilar alloy is difficult to be joined by FSW, and some defects such as cracks and grooves are easy to occur. When the rotational speed of stir head(n) is 750r/min and 950r/min, the welding speed(v) is 118mm/min or 150mm/min, a good formation of weld surface can be obtained, but the bonding of titanium/aluminum interface in the cross-section of weld joint is bad when n is 750r/min which results in a low strength joint. When n is 950r/min and v is 118mm/min,the strength of the FSW joint of Titanium/Aluminum dissimilar materials is 131MPa which is the highest.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 279 ◽  
Author(s):  
Zhongwen Wu ◽  
Chunping Huang ◽  
Fencheng Liu ◽  
Chun Xia ◽  
Liming Ke

Repairing damaged parts using proper repairing methods has become an important means to reduce manufacturing and operational costs and prolong the service life of 34CrNiMo6 steel structures. In the conventional fusion repairing method, welding wire and powder are often used as filling materials. Filling materials are often expensive or difficult to find. Some metallurgical issues (such as solidification crack, higher distortion) were also found with these methods. At the same time, most of the equipment that requires welding wire and powder is expensive. In this study, a new method based on friction stir processing (FSP) was successfully employed to repair 34CrNiMo6 steel, using a block as filling material. Filling blocks are much cheaper than conventional fusion repair consumables. As a result of solid-state repair, this method can also avoid the metallurgical issues of fusion repair. The microstructure and mechanical properties of the repaired samples were investigated using OM (Optical Microscope), SEM, EDS (Energy Dispersive Spectroscopy), XRD, and a Vickers hardness electronic universal tensile tester. The results showed that 34CrNiMo6 steel was successfully repaired by this method, with no defect. Tensile tests showed that the maximum ultimate strength (UTS) was 900 MPa and could reach 91.8% of that of the substrate. The fracture mode of the tensile samples was ductile/brittle mixed fracture. Hence, the repairing method based on FSP appears to be a promising method for repairing castings.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ch. Mohana Rao ◽  
K. Mallikarjuna Rao

PurposeThe objective of the paper is to evaluate the fabrication process and to study the influence of process parameters of friction stir processing of 6061-TiB2-Al2O3 Aluminum alloy surface composite on microhardness tensile strength, and microstructure.Design/methodology/approachFriction stir processing method is used for attaining the desired mechanical properties, and selectively processed reinforcements to fabricate the samples. The Taguchi technique was used to optimize rotational speed, travel speed and volume percentage of reinforcement particles to enhance the mechanical properties of 6061-TiB2-Al2O3 Aluminum alloy composite.FindingsThe fabrication of surface composites through FSP allows new inventions in terms of material with enhanced surface layers without changing the base metal.Practical implicationsTo examine the behavior of the surface of the composites in the different zones, the practical implication consists of the use of different characterization techniques like optical microscopy and scanning microscopy for microstructural behavior and the measurement of hardness and tensile tests for mechanical behavior.Originality/valueThe research work consists of tool design and process parameters, which can affect the final product (microstructural changes), and the performance of the modified surface layer behavior was studied and presented.


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