As the forging counterpart of fusion-based additive processes, additive friction stir deposition offers a solid-state deformation processing route to metal additive manufacturing, in which every vo...

https://www.tandfonline.com/doi/pdf/10.1080/21663831.2020.1847211

Additive friction stir deposition: a deformation processing route to metal additive manufacturing

Welding is a major manufacturing process that joins two or more pieces of materials together through heating/mixing them followed by cooling/solidification. The goal of welding manufacturing is to join materials together to meet service requirements at lowest costs. Advanced welding manufacturing is to use scientific methods to realize this goal. This paper views advanced welding manufacturing as a three step approach: (1) pre-design that selects process and joint design based on available processes (properties, capabilities, and costs); (2) design that uses models to predict the result from a given set of welding parameters and minimizes a cost function for optimizing the welding parameters; and (3) real-time sensing and control that overcome the deviations of welding conditions from their nominal ones used in optimizing the welding parameters by adjusting the welding parameters based on such real-time sensing and feedback control. The paper analyzes how these three steps depend on process properties/capabilities, process innovations, predictive models, numerical models for fluid dynamics, numerical models for structures, real-time sensing, and dynamic control. The paper also identifies the challenges in obtaining ideal solutions and reviews/analyzes the existing efforts toward better solutions. Special attention and analysis have been given to (1) gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) as benchmark processes for penetration and materials filling; (2) keyhole plasma arc welding (PAW), keyhole-tungsten inert gas (K-TIG), and keyhole laser welding as improved/capable penetrative processes; (3) friction stir welding (FSW) as a special penetrative low heat input process; (4) alternating current (AC) GMAW and double-electrode GMAW as improved materials filling processes; (5) efforts in numerical modeling for fluid dynamics; (6) efforts in numerical modeling for structures; (7) challenges and efforts in seam tracking and weld pool monitoring; (8) challenges and efforts in monitoring of keyhole laser welding and FSW; and (9) efforts in advanced sensing, data fusion/sensor fusion, and process control using machine learning/deep learning, model predictive control (MPC), and adaptive control.

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Advanced Welding Manufacturing: A Brief Analysis and Review of Challenges and Solutions

Directed energy deposition (DED) has matured into an essential additive manufacturing (AM) branch. DED has been broadly implemented in the design and fabrication of novel materials. These include metals, ceramics, and composites. Successful DED operation requires a good understanding of many critical phenomena, including laser-material interactions, fundamentals of casting and solidification of alloys, welding metallurgy and joining interfaces, along with microstructure-mechanical properties relations. Also critical are powder flowability, heat transfer, and various machine-related parameters. Several review articles have been published in recent years on metal AM via powder bed fusion (PBF) and DED, focusing on either a specific material system, mapping the recent technologies for AM, or issues related to the deposition process or material properties. Yet, no recent review is dedicated to a comprehensive presentation of material systems, design, fabrication, challenges, and the relationship between microstructures and mechanical properties of various DED'ed material families. Since the DED-based approach is becoming popular to manufacture bimetallic and multi-material structures, repair high-value structures, and alloy design, this comprehensive review focuses on materials design via DED, including a survey of a variety of monolithic and multi-material compositions. Finally, the critical challenges and opportunities in this area are highlighted. 

http://manuscript.elsevier.com/S0921509322003744/pdf/S0921509322003744.pdf

Laser-based directed energy deposition (DED-LB) of advanced materials

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 af...

https://journals.sagepub.com/doi/pdf/10.1177/0021998319859427

Fabrication of bulk aluminum-graphene nanocomposite through friction stir alloying:

Laser Additive Manufacturing is relatively new in the manufacturing industry. This paper focuses on the effect of hybrid coatings of Al-Cu-Fe on a grade five titanium alloy (Ti6Al4V) using laser metal deposition (LMD) process at different laser power and scanning speeds. Icosahedral Al-Cu-Fe as quasicrystals are a relatively new class of materials which exhibit unusual atomic structure and useful physical and chemical properties. Ti6Al4V/Al-Cu-Fe composite were analysed using Optical microscopy, Scanning electron microscopy (SEM) with energy dispersive microscopy (EDS), indentation testing, X-Ray Diffraction (XRD), corrosion and wear testing. deposit width and height, heat affected zone (HAZ) height), dilution rate, aspect ratio and powder efficiency of each sample remarkably increased with increasing laser power due to the laser-material interaction. It was observed that there are higher number of aluminium and titanium presented in the formation of the composite. The indentation testing reveals that for both scanning speed of 0.8m/min and 1m/min, the mean hardness value decreases with increasing laser power. It was found that due to dilution effect, a part of Ti entered into molten pool from the substrate. The results indicate that Ti, Al 3 Ti, Ti 3 Al, CuTi 2 can be produced through the in situ metallurgical reactions during the LMD process.

Experimental investigation of laser metal deposited icosahedral Al-Cu-Fe coatings on grade five titanium alloy

The deterioration of materials during industrial application poses a serious threat to the materials structural integrity. A material’s susceptibility to wear and surface damage can be reduced by alteration of its surface chemistry, morphology and crystal structure. Therefore, modification of surface properties plays an important role in optimizing a material’s performance for a given application. Modern industrial applications require materials with special surface properties such as high hardness, wear and corrosion resistance, therefore materials engineers are vital to regularly examine how the microstructure of a material can be altered. Aluminium-based alloys have a wide application in the automotive, domestic and aerospace industries due to their excellent mechanical properties such as good weldability, sound castability and outstanding resistance to corrosion. The purpose of this research is to enhance inherent properties of the materials to create new products or improve on existing ones. The most effective engineering solution to prevent or minimize such surface region of a component is done by fibre lasers. It was concluded that Hypereutectic Al-Si alloys having transition metals are exceptional materials due to their specific properties. The addition of Cu, Fe, Cr, Si, Mg and Ni to Al-based alloys can improve the mechanical properties at both ambient and elevated temperatures.

/pdf/the-effects-of-rapid-cooling-on-the-improved-surface-3nlomz0cp3.pdf

The Effects of Rapid Cooling on the Improved Surface Properties of Aluminium Based Coatings by Direct Laser Deposition

Carbon steel is widely used in engineering applications due to its exceptional mechanical properties, and low cost. The fabrication technique employed to weld carbon steel plays a vital role in the final performance of the welded component when put into service. TIG welding is a generally accepted arc welding technique due to its ease and versatility coupled with its capacity to produce high-quality welds. It is the most desirable technique employed for welding plain carbon steel. This work aims to evaluate the influence of TIG welding process parameters on the mechanical and microstructural properties such as tensile strength, hardness, and microstructure of AISI 1008 carbon steel. The process parameters considered in this work were the TIG welding current, and gas flow rate. The tensile testing and the Vickers hardness testing have been carried out for the welded samples. The microstructural investigation was also carried out for the fusion zones (FZ) and the heat-affected zones (HAZ). The test results were analyzed, and emerging properties were compared for the various set of parameters. Welded specimen produced with 140 A, 15 L/mm had the highest hardness value. However, the highest average ultimate tensile strength of 432.89 MPA was produced from process parameters 180 A, 19 L/mm. Finer grain structures were seen in the fusion zones as compared to the heat-affected zones for all selected parameters.

Experimental Investigation of TIG-welded AISI 1008 Carbon Steel

In machining operations, surface morphology is a significant parameter in developing mechanical components, as the level of the surface roughness gives the consumer the notion of whether the product is well developed or not. Also, the surface roughness of the mechanical component will affect the component during machining operations. The application of coatings in cutting tools is very significant, as coatings will help in improving the cutting tool life as well as protect it from rapid wear and corrosion rate. This research work focuses on the investigation of the significance of TiN–Zn coatings on high-speed steel (HSS) when compared with non-coated HSS cutting tool on the surface morphology, machining parameters and machining time on 1060 aluminum alloy during the machining operation. Computer numerical control (CNC) program and excel software was employed to investigate the effects the Coated cutting tool, various depth of cut and such as 1, 1.5, 2, 2.5, and 3 mm and at a constant cutting speed of 1250 rpm, constant feed rate of 10 mm/rev, with machining time varies from 15 to 500 s on the machined surface morphology of the 1060 aluminum alloy. After each machining time, the average surface roughness was determined, from three-point of the work piece, that is the starting point, middle point, and the end point. The result shows that the TiN–Zn coated HSS cutting tool on the surface morphology of 1060 aluminum alloy was found to reduce surface roughness with about 15.5% and both minimum surface roughness of 0.96 and 1.06 µm was achieved for the TiN–Zn coated and uncoated HSS cutting tool, respectively, with cutting time of 15 s at 1 mm depth of cut, which is viable for machining operations.

Experimental Study of the Effect of TiN–Zn Coated High-Speed Steel Cutting Tool on Surface Morphology of AL1060 Alloy During Machining Operation

Direct laser metal deposition (DLMD) is an additive manufacturing technique that is favourable in industries such as aerospace, biomedical, sports and automotive. Its advanced three-dimensional printing via layer-by-layer additive of a material allows for high-dimensional accuracy of the manufacturing of a part, but the surface finishing is still a limitation for the technology. Complex geometrical parts can be manufactured or repaired by employing the technology. This study focuses on the DLMD of Ti–Al–Si–Cu-based composite coatings on Ti–6Al–4V substrate, with the processing parameters such as the laser power and scanning speed being varied, while the other parameters were invariant. The microstructural evolution was analysed, and its influence on the anisotropy of the mechanical properties, the hardness property, and the corrosion performance of the material was investigated. The results showed that at low laser power and scan speed of 900 W and 1.0 m/min of Ti–Al–13Si–6Cu, which had the highest addition of alloying content, the highest hardness and improvement on the substrate was achieved. Large intermetallics compounds were formed of which the grains varied between columnar and backbone-like structures. The composite coating with the best corrosion rate was Ti–Al–7Si–Cu at 1.305 × 10−3 mm/year.

Esther T. Akinlabi

Papers

The Effects of Rapid Cooling on the Improved Surface Properties of Aluminium Based Coatings by Direct Laser Deposition

Experimental Investigation of TIG-welded AISI 1008 Carbon Steel

Experimental Study of the Effect of TiN–Zn Coated High-Speed Steel Cutting Tool on Surface Morphology of AL1060 Alloy During Machining Operation

Study of Additive Manufactured Ti–Al–Si–Cu/Ti–6Al–4V Composite Coating by Direct Laser Metal Deposition (DLMD) Technique

Multi-Criteria Decision Analysis Towards the Selection of a Perfect Location for Establishing Crude Oil Refinery in Niger Delta Nigeria