On the High-Temperature Flow Response of Friction Stir Processed Magnesium Metal Matrix Composites

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Ali Hosseinzadeh ◽  
Guney Guven Yapici

Abstract In the current work, multi-pass friction stir processing (FSP) was utilized to fabricate samples of fine-grained aluminum–zinc (AZ) magnesium alloy and its metal matrix composite (MMC). The microstructure and high-temperature tensile behavior of friction stir processed (FSPed) AZ31 and AZ31/SiC MMC at various strain rates in the range of 10−2 to 10−4 s−1 were investigated, and the fracture mechanisms of each condition were analyzed. The results verified that MMC samples exhibited a remarkable enhancement in microhardness. The evolution of inclined basal texture was observed after processing for both FSPed and MMC samples. The ambient temperature stress–strain response revealed that the formability of AZ31 has improved after friction stir processing, whereas high-temperature flow curves were discernibly sensitive to strain rate. Equiaxed deep dimples were detected on the fracture surfaces of FSPed samples, but decreased strain rate led to an increase in the number of dimples as attributed to the recrystallization of new grains.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Srinivas Prabhu ◽  
Padmakumar Bajakke ◽  
Vinayak Malik

Purpose In-situ aluminum metal matrix composites (AMMC) have taken over the use of ex-situ AMMC due to the generation of finer and thermodynamically stable intermetallic compounds. However, conventional processing routes pose inevitable defects like porosity and agglomeration of particles. This paper aims to study current state of progress in in-situ AMMC fabricated by Friction Stir Processing. Design/methodology/approach Friction stir processing (FSP) has successfully evolved to be a favorable in-situ composite manufacturing technique. The dynamics of the process account for a higher plastic strain of 35 and a strain rate of 75 per second. These processing conditions are responsible for grain evolution from rolled grain → dislocation walls and dislocation tangles → subgrains → dislocation multiplication → new grains. Working of matrix and reinforcement under ultra-high strain rate and shorter exposure time to high temperatures produce ultra-fine grains. Do the grain evolution modes include subgrain boundaries → subgrain boundaries and high angle grain boundaries → high angle grain boundaries. Findings Further, the increased strain and strain rate can shave and disrupt the oxide layer on the surface of particles and enhance wettability between the constituents. The frictional heat generated by tool and workpiece interaction is sufficient enough to raise the temperature to facilitate the exothermic reaction between the constituents. The heat released during the exothermic reaction can even raise the temperature and accelerate the reaction kinetics. In addition, heat release may cause local melting of the matrix material which helps to form strong interfacial bonds. Originality/value This article critically reviews the state of the art in the fabrication of in-situ AMMC through FSP. Further, FSP as a primary process and post-processing technique in the synthesis of in-situ AMMC are also dealt with.


2021 ◽  
Author(s):  
Vipin Sharma ◽  
Yogesh Dewang ◽  
Pardeep Kumar Nagpal ◽  
Suresh Kumar

Abstract Metal matrix composites are an important class of material that is developing rapidly to fulfil the diversified engineering requirements. The metal matrix composites are attractive owing to superior properties as compared to monolithic material. Their properties are dependent on various factors and fabrication techniques. The metal matrix composites are associated with several issues which hinder their full potential. In the present study friction stir processing is applied on the metal matrix composite as a post-processing operation. The friction stir processing offers many advantages owing to the solid-state nature of the processing. Stir cast metal matrix composites are prepared by using zircon sand particles of 50 µm in the matrix of LM13 aluminium alloy. The friction stir processing is applied on the metal matrix plates at a constant rotational speed and traverse speed of 1400 rpm and 63 mm/min, respectively. Multiple passes of friction stir processing are applied to elucidate the effect of the number of passes on microstructural modification. Microstructural examination showed a significant improvement in eutectic silicon morphology and distribution of zircon sand particles. A more than 5 times reduction as compared to the initial size was observed in the zircon sand particles after four passes of friction stir processing. The processed metal matrix composite also exhibits improvement in tensile strength and hardness.


2016 ◽  
Vol 4 (1) ◽  
pp. 52-61 ◽  
Author(s):  
B. Ratna Sunil ◽  
G. Pradeep Kumar Reddy ◽  
Hemendra Patle ◽  
Ravikumar Dumpala

2010 ◽  
Vol 154-155 ◽  
pp. 1761-1766 ◽  
Author(s):  
Mohsen Barmouz ◽  
M.K. Besharati Givi ◽  
Jalal Jafari

Friction stir processing (FSP) is a metal-working technique that causes microstructural modification and change in the upper surface of metal components. In this work the effects of tool pin profile on the microstructure and mechanical behavior of reinforced SiC particles metal matrix composites (MMCs) produced by friction stir processing were studied. Optical microscopy (OM) and Scanning electron microscopy (SEM) was employed to carry out the microstructural observations. Vickers Microhardness Machine used for microhardness evaluation. Results show that, tool pin profile play a major role in improvement of the surface quality, SiC particles dispersion in pure copper matrix, hardness behavior and wear resistance. Two different tool pin profile (straight cylindrical and square) were used to perform the process. It was found that, straight cylindrical tool pin profile led to finer grains, uniform dispersion of SiC particles, higher microhardness and wear resistance values.


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