Friction stir welding/processing (FSW/P) involving temperature, mechanics, metallurgy and interaction, is a complex solid state joining and processing technology. FSW has been widely applied to join aluminum alloy, titanium alloy and other materials which are difficult to weld by fusion welding. The last scientific study states that FSW has potential to join thermoplastic polymers and polymer matrix composites. In this review, current understanding and development about FSW of thermoplastic polymers and polymer matrix composites, multifunctional composites fabrication as well as dissimilar FSW of metal and polymer are reviewed. Future scientific research and engineering development related to FSW/P of thermoplastic polymers and polymer matrix composites are identified.

Friction stir welding/processing of polymers and polymer matrix composites

Biomedical materials and techniques to improve the tribological, mechanical and biomedical properties of orthopedic implants – A review article

Copper and aluminum materials are extensively used in different industries because of its great conductivities and corrosion resistant nature. It is important to join dissimilar materials such as c...

A Review on Dissimilar Friction Stir Welding of Copper to Aluminum: Process, Properties, and Variants

This paper presents a review on the resistance spot welding (RSW) of Al/Al alloys, Al alloys/steel, Al/Mg alloys, and Al/Ti alloys, with focus on structure, properties, and performance relationships. It also includes weld bonding, effect of welding parameters on joint quality, main metallurgical defects in Al spot welds, and electrode degradation. The high contact resistance, induced by the presence of oxide layer on the surface of Al alloys, and the need for application of high welding current during RSW of Al alloys result in rapid electrode tip wear and inconsistency in weld quality. Studies have shown that cleaning the oxide layer, sliding of a few microns between sheets, enhancing the electrode force, and the application of a low-current pre-heating can significantly reduce the contact resistance and improve joint quality. For Al/steel dissimilar RSW, the technique of resistance element welding, the use of optimized electrode morphology, the technique of RSW with cover plates, and the use of interlayers such as Al-Mg, AlSi12, and AlCu28 alloys were found to suppress the formation of brittle intermetallic compounds (IMC) and improve the joint quality. The employment of pure Ni foil, Au-coated Ni foil, Sn-coated steel, and Zn-coated steel interlayers was also found to restrict the formation of brittle IMCs during RSW of Al/Mg alloys. Furthermore, the techniques of RSW with cover plates and RSW under the influence of electromagnetic stirring effect were found to improve the weldability of Al/Ti dissimilar alloys.

A review on resistance spot welding of aluminum alloys

Aluminium AL6061-T6 is a common alloy which is used for many purposes since it has the superior mechanical properties such as hardness and weldability. It is commonly used in aircraft, automotive and packaging food industries. Milling of Al6061-T6 would be a good process especially in producing varieties shape of products to adapt with different applications. The capability of the CNC milling machine to make batch production would be a noteworthy advantage. However, the demand for high quality focuses attention on product quality, especially the roughness of the machined surface, because of its effect on product appearance, function and reliability. Introducing correct lubrication in the machining zone could improve the tribological characteristic of Al6061-T6 leading to higher product quality. In this research work, the optimum SiO2 nanolubrication parameters in milling of Al6061-T6 are investigated to achieve correct lubrication conditions for the lowest cutting force, cutting temperature and surface roughness. These parameters include nanolubricant concentration, nozzle angle and air carrier pressure. Taguchi optimization method is used with standard orthogonal array L16(4)3. Furthermore, analyses on surface roughness and cutting force are conducted using signal-to-noise (S/N) response analysis and the analysis of variance (Pareto ANOVA) to determine which process parameters are statistically significant. Finally, confirmation tests were carried out to investigate the optimization improvements.

An investigation of optimum SiO2 nanolubrication parameters in end milling of aerospace Al6061-T6 alloy

This paper presents a review on resistance spot welding of magnesium alloys, with emphasis on the relationship between microstructure, properties, and performance, under quasi-static and dynamic loading conditions. It also compares the resistance spot welding of magnesium-to-aluminum alloys and the various techniques used to suppress the formation of brittle intermetallic compounds. Resistance spot welding of magnesium-to-steel, weld bonding, the effects of process parameters on joint quality, and the main metallurgical defects in resistance spot welding of magnesium alloys are also deliberated. Studies have shown that the pre-existence of coarse second phase particles in the base metal, the addition of particles, such as titanium powder, and welding under the influence of electromagnetic stirring effect can promote columnar-to-equiaxed transition, microstructure refinement, and improvement in mechanical properties of magnesium alloys resistance spot welds. For magnesium-to-aluminum alloys spot welds, the use of interlayers, such as pure nickel, gold-coated nickel foil, and zinc-coated steel, was found to suppress the formation of brittle intermetallic compounds and thus significantly improve the joint strength.

A review on resistance spot welding of magnesium alloys

In this paper, the effects of process parameters, such as the tool rotational and traverse speeds, on temperature evolution and the microstructural and mechanical properties of dissimilar friction stir welding between 3 mm thick AA 7075 aluminum alloy and polycarbonate (PC) plates were investigated. The tool rotational and traverse speeds were varied from 3000 to 3500 rpm and 50 to 150 mm min−1, respectively. The joint fabricated at 3250 rpm and 100 mm min−1 yielded a highest tensile load of 586 N. Microstructural analysis of the stir zone revealed an interlock phenomenon, the transportation of AA 7075 in polycarbonate, and the absence of ceramic-type (carbide, hydride or oxide) compounds. Microhardness (HV) measurement on the weld zone showed an uneven distribution due to the complicated microstructure of the welded joint. The maximum temperatures of 164°C and 66°C were obtained at 3250 rpm and 100 mm min−1 at a distance of 5 mm away from the welding centerline in the AA 7075 and PC side, respec...

Dissimilar friction stir welding between polycarbonate and AA 7075 aluminum alloy

Nowadays, the demand for high product quality focuses extensive attention to the quality of machined surface. The (CNC) milling machine facilities provides a wide variety of parameters set-up, making the machining process on the glass excellent in manufacturing complicated special products compared with other machining processes. However, the application of grinding process on the CNC milling machine could be an ideal solution to improve the product quality, but adopting the right machining parameters is required. Taguchi optimization method was used to estimate optimum machining parameters with standard orthogonal array L16 (44) to replace the conventional trial and error method as it is time-consuming. Moreover, analyses on surface roughness and cutting force are applied which are partial determinant of the quality of surface and cutting process. These analyses are conducted using signal to noise (S/N) response analysis and the analysis of variance (Pareto ANOVA) to determine which process parameters are statistically significant. In glass milling operation, several machining parameters are considered to be significant in affecting surface roughness and cutting forces. These parameters include the lubrication pressure, spindle speed, feed rate, and depth of cut as control factors. While, the lubrication direction is considered as a noise factor in the experiments. Finally, verification tests are carried out to investigate the improvement of the optimization. The results showed an improvement of 49.02% and 26.28% in the surface roughness and cutting force performance, respectively.

M. Fadzil

Papers

A review on resistance spot welding of aluminum alloys

A review on resistance spot welding of magnesium alloys

Dissimilar friction stir welding between polycarbonate and AA 7075 aluminum alloy

Enhancement and verification of a machined surface quality for glass milling operation using CBN grinding tool—Taguchi approach

Employment of fiber laser technology to weld austenitic stainless steel 304 l with aluminum alloy 5083 using pre-placed activating flux