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The purpose of this paper is to propose two simple tools for the kinematic characterization of hexapods. The paper also aims to share the experience of converting a popular commercial motion base (Stewart‐Gough platform, hexapod) to an industrial robot for use in heavy duty aerospace manufacturing processes.

The complete workspace of a hexapod is a six‐dimensional entity that is impossible to visualize. Thus, nearly all hexapod manufacturers simply state the extrema of each of the six dimensions, which is very misleading. As a compromise, a special 3D subset of the complete workspace is proposed, an approximation of which can be readily obtained using a computer‐aided design (CAD)/computer‐aided manufacturing (CAM) software suite, such as computer‐aided 3D interactive application (CATIA). While calibration techniques for serial robots are readily available, there is still no generally agreed procedure for calibrating hexapods. The paper proposes a simple calibration method that relies on the use of a laser tracker and requires no programming at all. Instead, the design parameters of the hexapod are directly and individually measured and the few computations involved are performed in a CAD/CAM software such as CATIA.

The conventional octahedral hexapod design has a very limited workspace, though free of singularities. There are important deviations between the actual and the specified kinematic model in a commercial motion base.

A commercial motion base can be used as a precision positioning device with its controller retrofitted with state‐of‐the‐art motion control technology with accurate workspace and geometric characteristics.

A novel geometric approach for obtaining meaningful measures of the workspace is proposed. A novel, systematic procedure for the calibration of a hexapod is outlined. Finally, experimental results are presented and discussed.

Unconventional machining processes, particularly ultrasonic vibration cutting (UVC), can overcome such technical bottlenecks. However, the precise mechanism through which UVC affects the in-service functional performance of advanced aerospace materials remains obscure. This limits their industrial application and requires a deeper understanding.

The surface integrity and in-service functional performance of advanced aerospace materials are important guarantees for safety and stability in the aerospace industry. For advanced aerospace materials, which are difficult-to-machine, conventional machining processes cannot meet the requirements of high in-service functional performance owing to rapid tool wear, low processing efficiency and high cutting forces and temperatures in the cutting area during machining.

To address this literature gap, this study is focused on the quantitative evaluation of the in-service functional performance (fatigue performance, wear resistance and corrosion resistance) of advanced aerospace materials. First, the characteristics and usage background of advanced aerospace materials are elaborated in detail. Second, the improved effect of UVC on in-service functional performance is summarized. We have also explored the unique advantages of UVC during the processing of advanced aerospace materials. Finally, in response to some of the limitations of UVC, future development directions are proposed, including improvements in ultrasound systems, upgrades in ultrasound processing objects and theoretical breakthroughs in in-service functional performance.

This study provides insights into the optimization of machining processes to improve the in-service functional performance of advanced aviation materials, particularly the use of UVC and its unique process advantages.

The purpose of this paper is to investigate the combination of selective laser melting (SLM) and 5-axis CNC milling to produce parts from titanium powder. The aim is to achieve a more resource-efficient manufacturing process by reducing material wastage and machining time, while adhering to quality requirements.

A benchmark titanium aerospace component is manufactured with two different approaches using subtractive and additive manufacturing technologies. The first component is produced from a solid billet using only 5-axis CNC milling. The second component is grown from powder using SLM to produce a net-shaped part of which the final shape and part accuracy are achieved through 5-axis CNC milling. The potential saving of material and machining time of the process combination is evaluated by comparing it to the conventional purely CNC approach. The form accuracy, surface finish, mechanical properties and tool wear for the two processes are also compared.

The results show that the process combination can be used to produce Ti components that adhere to aerospace standards. With the process combination, a material saving of 87 per cent was achieved along with a reduction of 21 per cent in machining time. Further improvements are possible using optimized SLM build and machining strategies.

This paper presents the results of a resource efficiency assessment on the combination of SLM and 5-axis CNC milling for the titanium alloy, Ti6Al4V. It is expected that this process combination can make a significant contribution towards reducing material wastage and machining time for aerospace applications.

This study aims to use nanofluid-based minimum quantity lubrication (NMQL) technique to minimize the use of cutting fluids in machining of Inconel-625 and Stainless Steel 304 (SS-304) (Ni-Cr alloys).

Machining of Ni-Cr-based alloys is very challenging as these exhibit lower thermal conductivity and rapid work hardening. So, these cannot be machined dry, and a suitable cutting fluid has to be used. To improve the thermal conductivity of cutting fluid, multi-walled carbon nanotubes (MWCNTs) were added to the soybean oil and used with MQL. This study attempts to compare tool wear of coated carbide inserts during face milling of Inconel-625 and SS-304 under dry, flooded and NMQL conditions. The machining performance of both materials, i.e. Inconel-625 and SS-304, has been compared on the basis of tool wear behavior evaluated using scanning electron microscopy-energy dispersive spectroscopy.

The results indicate higher tool wear and lower tool life during machining of Inconel-625 as compared to SS-304. Machining of Inconel-625 exhibited non-consistent tool wear behavior. The tool failure modes experienced during dry machining are discrete fracture, cracks, etc., which are completely eliminated with the use of NMQL machining. In addition, less adhesion wear and abrasion marks are noticed as compared to dry and flooded machining, thereby enhancing the tool life.

Inconel-625 and SS-304 have specific applications in aircraft and aerospace industry, where sculptured surfaces of the turbine blades are machined. The results of current investigation will provide a rich data base for effective machining of both materials under variety of machining conditions.

The literature review indicated that majority of research work on MQL machining has been carried out to explore machining of Ni-Cr alloys such as Inconel 718, Inconel 800, AISI4340, AISI316, AISI1040, AISI430, titanium alloys, hardened steel alloys and Al alloys. Few researchers have explored the suitability of nanofluids and vegetable oil-based cutting fluids in metal cutting operation. However, no literature is available on face milling using nanoparticle-based MQL during machining Inconel-625 and SS-304. Therefore, experimental investigation was conducted to examine the machining performance of NMQL during face milling of Inconel-625 and SS-304 by using soybean oil (vegetable oil) with MWCNTs to achieve ecofriendly machining.

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.

Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.

In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.

With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.

Glass is a brittle material produced from silica, which has fine material properties, Owing to its sophisticated material properties, glass has found wide application in various high-technological fields such as aviation, aerospace, communication, optics, biomedical and electronics. However, glass is known as difficult to machine material because of its tendency to brittle fracture during machining. This paper aims to investigate the effects of cutting parameters on surface quality and machining time during micro-milling of brittle glass components.

A comprehensive genetic algorithm-based optimization strategy is used for selection of process parameters such as cutting speed, feed rate and depth of cut. Effectiveness of the proposed strategy is validated by conducting micro-milling cutting experiments on soda-lime glass material.

Results showed that the generated surface quality drastically decrease with increase in the amount of removed material. Lower depth of cut and feed rate result in less amount of cracks formed on machined surface. Also, it is observed that the increase in cutting speed results in better surface quality. Having desired surface quality in shorter machining time directly reduces energy consumed during manufacturing, which is reducing environmental impact of glass parts.

The novelty of this research work lies in simultaneously considering the effects of cutting speed, feed rate, depth of cut on surface quality and machining time for micro-milling operation of brittle glass material. The model is able to find optimum process parameters for high surface quality and minimum machining time.

STELLRAM's first introduction in a new series of tooling ranges is the H‐Elix milling programme specifically developed for the machining of exotic, heat‐resistant materials such as those used in aerospace. Now available ex‐stock from Stellram Ltd of Melksham, Wiltshire, H‐Elix cutters include end and face mills which feature through‐tool coolant supply and cover diameters from 16 to 100 mm. Innovative design coupled with high‐performance inserts result in a cutter which exerts lower forces on both machine tool and component. High positive geometry is ideal for machining difficult materials and maximum advantage is taken in the new range for high efficiency cutting of Titanium, Inconel, Marval, Stellite and other exotics.

The purpose of this paper is to report the preparation, characterisation and machinability of resin hybrid GFRP composites, which are made of glass fibre and the mixture of epoxy & polyester resin.

Resin hybrid GFRP laminates containing 0, 20 and 40wt% of polyester resin with the epoxy resin are prepared by conventional hand layup technique using glass fibre as the reinforcement. The variation of break load and shear strength for three different combinations of epoxy and polyester resin are studied by ASTM. A plan of experiment based on Taguchi was established with prefixed cutting parameters and the machining was performed. A stylus type profilometer to examine the surface roughness and shop microscope to examine the delamination of resin hybrid GFRP laminates were used. An analysis of variance (ANOVA) was performed to investigate the cutting characteristics of resin hybrid GFRP composite materials using solid carbide end mill. The correlation was obtained by multiple‐variable linear regression using Minitab 14 software.

Taguchi analysis reveals that the resin hybrid GFRP laminate provides better machinability in terms of surface roughness and delamination when compared to homogenous GFRP laminates (pure epoxy resin). Polyester resin enhances the machinability of the GFRP laminates.

The machinability of the resin hybrid GFRP laminates can be improved further by modifying the polyester resin percentage.

The resin hybrid GFRP laminates so developed can be used in aircraft and aerospace applications to increase the shear and work of fracture properties.

This study aims to review the recent advancements in high entropy alloys (HEAs) called high entropy materials, including high entropy superalloys which are current potential alternatives to nickel superalloys for gas turbine applications. Understandings of the laser surface modification techniques of the HEA are discussed whilst future recommendations and remedies to manufacturing challenges via laser are outlined.

Materials used for high-pressure gas turbine engine applications must be able to withstand severe environmentally induced degradation, mechanical, thermal loads and general extreme conditions caused by hot corrosive gases, high-temperature oxidation and stress. Over the years, Nickel-based superalloys with elevated temperature rupture and creep resistance, excellent lifetime expectancy and solution strengthening L12 and γ´ precipitate used for turbine engine applications. However, the superalloy’s density, low creep strength, poor thermal conductivity, difficulty in machining and low fatigue resistance demands the innovation of new advanced materials.

HEAs is one of the most frequently investigated advanced materials, attributed to their configurational complexity and properties reported to exceed conventional materials. Thus, owing to their characteristic feature of the high entropy effect, several other materials have emerged to become potential solutions for several functional and structural applications in the aerospace industry. In a previous study, research contributions show that defects are associated with conventional manufacturing processes of HEAs; therefore, this study investigates new advances in the laser-based manufacturing and surface modification techniques of HEA.

The AlxCoCrCuFeNi HEA system, particularly the Al0.5CoCrCuFeNi HEA has been extensively studied, attributed to its mechanical and physical properties exceeding that of pure metals for aerospace turbine engine applications and the advances in the fabrication and surface modification processes of the alloy was outlined to show the latest developments focusing only on laser-based manufacturing processing due to its many advantages.

It is evident that high entropy materials are a potential innovative alternative to conventional superalloys for turbine engine applications via laser additive manufacturing.