Friction stir welding/processing of metals and alloys: A comprehensive review on microstructural evolution

Magnesium (Mg) alloys have been extensively used in various fields, such as aerospace, automobile, electronics, and biomedical industries, due to their high specific strength and stiffness, excellent vibration absorption, electromagnetic shielding effect, good machinability, and recyclability. Friction stir processing (FSP) is a severe plastic deformation technique, based on the principle of friction stir welding. In addition to introducing the basic principle and advantages of FSP, this paper reviews the studies of FSP in the modification of the cast structure, superplastic deformation behavior, preparation of fine-grained Mg alloys and Mg-based surface composites, and additive manufacturing. FSP not only refines, homogenizes, and densifies the microstructure, but also eliminates the cast microstructure defects, breaks up the brittle and network-like phases, and prepares fine-grained, ultrafine-, and nano-grained Mg alloys. Indeed, FSP significantly improves the comprehensive mechanical properties of the alloys and achieves low-temperature and/or high strain rate superplasticity. Furthermore, FSP can produce particle- and fiber-reinforced Mg-based surface composites. As a promising additive manufacturing technique of light metals, FSP enables the additive manufacturing of Mg alloys. Finally, we prospect the future research direction and application with friction stir processed Mg alloys.

Friction Stir Processing of Magnesium Alloys: A Review

Friction stir processing (FSP) is a rapidly emerging newer solid-state technique for composite fabrication. It involves surface modification which in turn enables successful adaptation of surface p...

A Review of Recent Progress in Solid State Fabrication of Composites and Functionally Graded Systems Via Friction Stir Processing

Magnesium matrix composite reinforced by nanoparticles – A review

Development of titanium particulate reinforced AZ31 magnesium matrix composites via friction stir processing

https://cyberleninka.org/article/n/1336791.pdf

Magnesium based surface metal matrix composites by friction stir processing

In the present study, influence of friction stir processing (FSP) tool pin profile on the microstructure evolution, corrosion and machining characteristics of the AZ91 magnesium alloy was investigated. Three different pin profiles namely simple taper, threaded taper and square taper were selected and FSP was carried out at 1400 rpm and 25 mm/min tool travel speed. Microstructural observations indicated grain refinement from a starting grain size of 166.5–7.9, 22.1 and 4.08 µm for FSPed samples processed by simple taper, threaded taper and square taper pins, respectively. In all the FSPed samples, decreased amount of secondary phase (Mg17Al12) was observed compared with that of the unprocessed sample. From the X-ray diffraction analysis, it was observed that the square taper pin tool had induced higher texture effect compared with the other two FSP tools. From the electrochemical studies, the corrosion resistance of the sample processed with square taper pin tool was observed to be more in comparison to that of the other samples; which could be attributed to the texture effect and decreased fraction of secondary phase. Machining behavior assessed by conducting drilling experiments showed a significant influence of grain refinement on the cutting forces.

Machining Characteristics and Corrosion Behavior of Grain Refined AZ91 Mg Alloy Produced by Friction Stir Processing: Role of Tool Pin Profile

In the present study, AA7075-T6 based surface composites reinforced with (i) B4C and (ii) B4C/MoS2 particles were fabricated using friction stir processing (FSP). Microstructural characteristics of the samples were studied by using optical microscope and scanning electron microscope. It is evident from the microstructural observations that the addition of MoS2 particles improved the uniform distribution of B4C particles in the matrix material. However, lower hardness values were observed for the surface composites compared with that of the base metal, despite the particles reinforcement. This can be explained by considering the effect of FSP on altering the amount of intermetallic phase present in AA7075. In order to improve the hardness, T6 heat treatment (solution treatment at 515 °C for 0.5 h, quenching in cold water and artificial aging at 120 °C for 24 h) was carried out for the fabricated surface composites. Sliding wear characteristics of the samples were investigated against AISI 52100 steel ball using linear reciprocating tribometer. Heat-treated (T6) FSPed composites exhibited superior wear resistance in comparision to that of the base alloy and FSPed composites.

https://iopscience.iop.org/article/10.1088/2053-1591/ab1ff4/pdf

Hardness and sliding wear characteristics of AA7075-T6 surface composites reinforced with B4C and MoS2 particles

https://iopscience.iop.org/article/10.1088/2053-1591/ab6a55/pdf

Hemendra Patle

Papers

Magnesium based surface metal matrix composites by friction stir processing

Machining Characteristics and Corrosion Behavior of Grain Refined AZ91 Mg Alloy Produced by Friction Stir Processing: Role of Tool Pin Profile

Hardness and sliding wear characteristics of AA7075-T6 surface composites reinforced with B4C and MoS2 particles

Sliding wear behavior of AZ91/B4C surface composites produced by friction stir processing

Machining characteristics, wear and corrosion behavior of AZ91 magnesium alloy ‐ fly ash composites produced by friction stir processing