Friction stir processing of Al6061- SiC -graphite hybrid surface composites

Journal of Composite Materials

Paul

2019

Self Cite

Friction stir alloying is primarily employed for the fabrication of surface composite to improve surface properties like hardness, wear resistance, and corrosion resistance without significantly affecting the bulk properties of the alloy. The present study demonstrates the novel method for the fabrication of bulk aluminum-graphene nanoplatelets composite by using friction stir alloying. Here, the novelty is shown through the method of graphene nanoplatelets incorporation in the stir zone. For this purpose, a channel is fabricated on the cross-sectional surface of the aluminum plate and filled with graphene nanoplatelets. It is then covered by the cross-sectional surface of another aluminum plate of same dimensions and friction stir alloying is carried out. Reference material (RM) is also fabricated at the same parameters without any graphene nanoplatelet reinforcements for the performance evaluation of the nanocomposite. The microhardness of the fabricated composite increased by ∼57% as compared to the reference material. However, the tensile strength of the fabricated Al-graphene nanoplatelet composites decreased marginally as compared to reference material. The strengthening of the composite is explained systematically by various mechanisms. The results of microhardness and tensile test were corroborated with various characterization methods such as optical micrographs, scanning electron microscopy, atomic force microscope, and X-ray diffraction.

Section: Graphene Morphologymentioning

confidence: 99%

Fabrication of bulk aluminum-graphene nanocomposite through friction stir alloying

Journal of Composite Materials

Paul

2019

Self Cite

“…In hybrid surface metal matrix composites, wear resistance can be enhanced through the combined effect of stiff ceramic and solid lubricant powder reinforcements. Different investigators explored aluminumbased hybrid surface composites with various arrangements of reinforcement powders [40][41][42][43][44][45][46]. Compared to dry mixing, the solvent-based particle mixing strategy displayed better properties attributed to even mixing and de-agglomeration of particle clusters [44].…”

Section: Introductionmentioning

confidence: 99%

Different reinforcement strategies of hybrid surface composite AA6061/(B₄C+MoS₂) produced by friction stir processing

Materialwissenschaft Werkst

Patel

Badheka

et al. 2020

Aluminum surface composites have gained huge importance in material processing due to their noble tribological characteristics. The reinforcement of solid lubricant particles with hard ceramics further enriches the tribological characteristics of surface composites. In the current study, friction stir processing was chosen to synthesize hybrid surface composites of aluminum containing B 4 C and MoS 2 particles with anticipated improved tribological behavior. B 4 C and MoS 2 powder particles in 87.5: 12.5 ratio were reinforced into the AA6061 by hole and groove method. Microstructural observations indicated that reinforcement particles are well distributed in the matrix. The hardness and wear resistance of hybrid surface composites improved as compared to the base material, due to well distributed abrasive B 4 C and solid lubricant MoS 2 particles in AA6061. The hybrid surface composites achieved~32 % increased average hardness as compared to the base material. Hole method revealed~13 % better wear resistance compared to the groove method for friction stir processed hybrid surface composite, attributing to an improved homogeneity of particle distribution shown by zigzag hole pattern. Moreover, friction stir processed AA6061 without reinforcement particles exhibited reduced hardness and wear resistance due to loss of strengthening precipitates during multi-pass friction stir processing.

“…Various carbonaceous filler materials explored by researchers for the fabrication of Al-based composites include graphite, graphene, graphene nano sheets/platelets (GNPs) and carbon nanotubes (CNTs). 1–5 Graphene which is a two dimensional form of carbon (2D) can be considered as the building blocks for the other forms of carbon. The graphene can be stacked to form three dimensional (3D) graphite or can be rolled to form the one dimensional (1D) CNTs.…”

Section: Introductionmentioning

confidence: 99%

Particle size and shape effects on the surface mechanical properties of aluminium coated with carbonaceous materials

Sahoo

Joseph

Journal of Composite Materials

et al. 2018

Self Cite

Influence of particle size and shape of carbonaceous materials on the surface mechanical properties of Aluminium-1100 substrates is evaluated. The aluminium surface is impregnated with multiwalled carbon nanotubes (one dimensional), Graphene nanoplatelets (two dimensional) and graphite flakes (three dimensional) of various sizes. An electrical resistance heat assisted pressing technique was used for localised melting of the aluminium substrate followed by the mechanical impregnation of the carbonaceous materials. Surface mechanical properties of the so obtained surface composites were evaluated by microhardness and nanoindentation studies. A general observation is that the indentation hardness and Young’s modulus increase as the shape changes from three dimensional to one dimensional and also with the reduction in particle size. The maximum surface hardness achieved for each of these particles and the processing conditions at which the best properties are attained give insights into the prevailing hardening mechanisms. Raman spectroscopic analysis, which shows a variable shift and change in intensity ratios of the corresponding G, D and 2D bands, corroborates the experimental observations.