scholarly journals Investigation of Al-B4C Metal Matrix Composites Produced by Friction Stir Additive Processing

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2020
Author(s):  
Martin Zubcak ◽  
Jaroslav Soltes ◽  
Mariia Zimina ◽  
Thomas Weinberger ◽  
Norbert Enzinger

Aluminium—boron carbide metal matrix composites (Al-B4C MMCs) belong to the class of materials extensively used in the nuclear industry as a thermal neutron absorber in spent fuel casks. This article investigates a novel production method of Al-B4C MMCs—Friction Stir Additive Processing (FSAP)—as an alternative production method to casting or sintering. FSAP is derived from friction stir welding, which can be used to local modifications of microstructure, or it can be used to incorporate the second phase into the processed material. During this study, a variant of FSAP for MMC production was proposed, and its mechanical and thermal neutron absorbing properties have been investigated. Further, the influence of neutron irradiation on mechanical properties has been studied. Results show that FSAP can successfully produce Al-B4C MMCs with 7 mm thickness. Neutron irradiation causes only a slight increase in hardness, while its effect on tensile properties remains inconclusive.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3110
Author(s):  
Kaveripakkam Suban Ashraff Ali ◽  
Vinayagam Mohanavel ◽  
Subbiah Arungalai Vendan ◽  
Manickam Ravichandran ◽  
Anshul Yadav ◽  
...  

This study focuses on the properties and process parameters dictating behavioural aspects of friction stir welded Aluminium Alloy AA6061 metal matrix composites reinforced with varying percentages of SiC and B4C. The joint properties in terms of mechanical strength, microstructural integrity and quality were examined. The weld reveals grain refinement and uniform distribution of reinforced particles in the joint region leading to improved strength compared to other joints of varying base material compositions. The tensile properties of the friction stir welded Al-MMCs improved after reinforcement with SiC and B4C. The maximum ultimate tensile stress was around 172.8 ± 1.9 MPa for composite with 10% SiC and 3% B4C reinforcement. The percentage elongation decreased as the percentage of SiC decreases and B4C increases. The hardness of the Al-MMCs improved considerably by adding reinforcement and subsequent thermal action during the FSW process, indicating an optimal increase as it eliminates brittleness. It was seen that higher SiC content contributes to higher strength, improved wear properties and hardness. The wear rate was as high as 12 ± 0.9 g/s for 10% SiC reinforcement and 30 N load. The wear rate reduced for lower values of load and increased with B4C reinforcement. The microstructural examination at the joints reveals the flow of plasticized metal from advancing to the retreating side. The formation of onion rings in the weld zone was due to the cylindrical FSW rotating tool material impression during the stirring action. Alterations in chemical properties are negligible, thereby retaining the original characteristics of the materials post welding. No major cracks or pores were observed during the non-destructive testing process that established good quality of the weld. The results are indicated improvement in mechanical and microstructural properties of the weld.


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.


Sign in / Sign up

Export Citation Format

Share Document