Plastic and metal can be directly bonded via insert injection molding by creating surface porous structures with 30–50 nm sizes on metal surface. Molten polymers can be penetrated into the small pores created on metal surface in the short molding process, and strong joint can be obtained. The bonding mechanism of aluminum alloy (Al5052) and polyphenylene sulfide (PPS) with two different surface features of Al5052 was studied. Scanning transmission electron microscopy (STEM) was performed to investigate the interfacial structures in terms of elemental distributions and three-dimensional (3D) inter-connectivity of the pores on the Al5052, and the chemical reaction which takes place during the joint process was investigated by X-ray photon spectroscopy (XPS). The properties of the joint interfaces were evaluated to discuss the effect of interfacial structures on the joint properties.

To achieve a stable and high wear resistive functional surface under dry sliding friction, the present study proposes micro-textured diamond-like carbon coatings fabricated by ionized physical vapor deposition (I-PVD) using metallic masks. To clarify the suitable geometrical design under dry sliding friction, geometrical quantities of textured array patterns are varied by using metallic masks with different circular hole array patterns fabricated by picosecond pulsed laser processing. The effect of texturing on friction and wear properties is evaluated by ball-on-disk type friction tests for the condition of a constant DLC-coverage per unit area. Thereby, textured DLC pattern with diameters of 50 μm, 100 μm, and 150 μm are applied. Within the first 10 000 laps stable and lower coefficient of friction is obtained with the smallest diameters of 50 μm. However, at further rotation of more than 40 000 laps, the wear of the smaller diameters becomes more pronounced due to the increase of stress concentration at the edge of the structure. Based on these findings, geometrical design of micro-textured DLC coating is discussed with regard to the suppression of three-body plowing and the prevention of stress concentration.

Highly integrated and closely tolerated functional components can be produced by sheet-bulk metal forming which is the application of bulk forming operations on sheet metal. These processes are characterized by a successive and/or simultaneous occurrence of different load conditions which reduce the geometrical accuracy of the parts. One challenge within sheet-bulk metal forming is the identification of methods to control the material flow to improve the product quality. A suitable approach is the local modification of the tribological conditions. Within this study, requirements regarding the needed adaption of the tribological system for a specific process were defined by numerical investigations. The results reveal that a local increase of the friction leads to an improved geometrical accuracy. Based on these results, abrasive blasting as a method to modify the tool surface and thus influencing the tribological behaviour was investigated. For the determination of the tribological mechanism of blasted tool surfaces, the influence of different blasting media as well as blasting pressures on the surface integrity and the friction were determined. Additionally, the functional stability of a modification was investigated. Finally, the correlations between surface properties and friction conditions were used to derive the mechanisms of blasted tool surfaces.

Ultrasonic evaluation for residual stress measurement has been an effective method owing to its easy implementation, low cost and intrinsically being nondestructive. The velocity variations of acoustic waves in materials can be related to the stress state in the deformed medium by the acoustoelastic effects. In this study, a laser/EMAT ultrasonic method is proposed to evaluate the surface/subsurface longitudinal residual stress distribution generated by gas metal arc welding (GMAW). The velocity variation ΔV/V of Rayleigh wave, which is a surface wave, will be experimentally measured. Q-Switched Nd:YAG laser is used to generate a broadband ultrasonic wave. An electromagnetic acoustic transducer (EMAT) is attached to the welding plate for Rayleigh wave pick up. As the ultrasound receiver, the EMAT is used to measure time of flight (ToF) of the Rayleigh waves traveling along a specific path parallel to the direction of the welding seam. ToF measurements are obtained by changing Rayleigh wave path to welding zone center distance from 0 to 45 mm. A 3D thermomechanical-coupled finite element model is then developed to validate the capability of the proposed technique for welding-induced residual stress evaluation. The distributions of the normalized velocity variations from ToF experiments are compared with the distribution of the normalized longitudinal residual stresses from finite element analysis (FEA). It has been shown that there is a good correlation between these two distributions. The proposed technique provides a potential nondestructive avenue for surface/subsurface residual stress evaluation for welding parts.

In this paper, an innovative and alternative concept of maskless micro-electrochemical texturing is exploited for the fabrication of simple and complex micropatterns. In this process, the tool is masked incorporated with the textured patterns and the workpiece has no mask. This research study concentrates on generation of simple micropattern, i.e. linear micropattern, and complex micropattern, i.e. cascade micropattern using maskless micro-electrochemical texturing method without repeated use of photolithography process. A single masked patterned tool with SU-8 2150 mask can produce many high-quality simple and complex micropatterns economically using this method. A well-planned experimental set-up consisting of electrochemical micromachining (EMM) cell, electrode fixtures, electrical connections and constricted vertical cross-flow electrolyte system has been designed and developed indigenously for carrying out the experiments. Influences of major influencing parameters, i.e. machining voltage, interelectrode gap, flow rate and machining time, are investigated on width overcut and machining depth of micropatterns. For higher machining accuracy, controlled depth and lower standard deviations, machining with lower machining time, lower voltage, lower interelectrode gap and higher flow rate is recommended. From the detailed experimental investigation, the best parametric combination are voltage of 8 V, duty ratio of 30%, pulse frequency of 15 kHz, electrolyte of NaCl (0.34 M) + NaNO3 (0.23 M), flow rate of 5.35 m3/h, interelectrode gap of 50 µm and machining time of 40 s.

Owing to its extraordinary range of properties, yttria-doped zirconia holds a unique place among the ceramic oxide systems. To improve the properties for some specific custom design applications, co-doping with other rare earth oxides such as ceria is needed. The aim of this paper is to identify the correlations between the phase composition evolution with increasing thermal treatment temperature in order to establish the thermal stability in connection with the ceria content and how does it influence the yttria-stabilised zirconia microstructure. The ZrO 2 –3Y 2 O 3 – n CeO 2 ( n = 3, 6 and 9 wt.%) samples were obtained by a hydrothermal process and submitted to a thermal treatment up to 1600 °C. Intensive characterization was performed via X-ray powder diffraction and EDX analysis. It was found that up to 400 °C, a monophasic structure was formed. At higher temperatures tetragonal zirconia is formed as a major phase with the presence of secondary monoclinic and cubic phases, depending on the Ce content and thermal treatment temperature. Sintered compacts with densities up to 99.5% from the theoretical density were obtained starting from the 6%CeO 2 –3%Y 2 O 3 –ZrO 2 -nanostructured powders using a special field-assisted (FAST) sintering process. With increasing CeO 2 content to 9% only, tetragonal zirconia with 6–9 nm crystallite sizes is formed during the FAST sintering process.

As a first step of applying additive manufacturing (AM) technology, plastic prototypes have been produced using various AM Process such as Fusion Deposition Modeling (FDM), Stereolithography (SLA) and other processes. After more research and development, AM has become capable of producing complex net shaped in materials which can be used in applicable parts. These materials include metals, ceramics, and composites. Polymers and metals are considered as commercially available materials for AM processes; however, ceramics and composites are still considered under research and development. In this study, a literature review on design for AM of composite materials and potential alloys is discussed. It is investigated that polymer matrix, ceramic matrix, metal matrix, and fiber reinforced are most common composites through AM. Furthermore, Functionally Graded Materials (FGM) is considered as an effective application of AM because AM offers the ability to control the composition and optimize the properties of the built part. An example of FGM through using AM technology is the missile nose cone which includes an ultra-high temperature ceramic graded to a refractory metal from outside to inside and it used for sustaining extreme external temperatures. During this work, different applications of AM on different classifications of composite materials are shown through studying of industrial objective, the importance of application, processing, results and future challenges.

We were all saddened by the loss of Professor He Yang, Associate Editor of Manufacturing Review, who passed away in 27th September 2016. His loss is a huge loss not only to the Chinese research community and his industrial collaborators but also to the scholars and researchers world-wide in engineering plasticity and technologies and journal of Manufacturing Review, manufacturing research in general.

The interfacial heat transfer coefficient (IHTC) is a key parameter in hot stamping processes, in which a hot blank is formed and quenched by cold dies simultaneously. The IHTC should therefore be identified and used in FE simulations to improve the accuracy of simulation results of hot stamping processes. In this work, a hot stamping simulator was designed and assembled in a Gleeble 3800 thermo-mechanical testing system and a FE model was built in PAM-STAMP to determine the IHTC values between a hot aluminium alloy 7075 blank and cold dies. The IHTC values were determined at different contact pressures under both dry and lubricated (Omega-35) conditions. In addition, a model to calculate the IHTC value at different contact pressures and area densities of lubricant was developed for the hot stamping process, which was proved to be working well with verification tests.

Electromagnetic micro-forming is a novel technology of micro-fabrication with high-energy rate which shows superiority in fabricating shallow and concave parts. In the research reported in this paper, micro electromagnetic bulging process was carried out with stainless steel foil, and the effects of discharge parameters and foil thickness on the deformation quality were analyzed. The results show that the surface quality and the forming depth of micro channels could be improved by increasing discharge energy and frequency. The discharge frequency has more effect on the micro electromagnetic forming quality. With the increase of the discharge frequency, the depth of micro channel reaches maximum value firstly and then decreases. The surface quality and depth of micro channel decreases with increase of the foil thickness. Optimum parameters arrays of micro channel with good surface quality and dimensional accuracy were obtained in the electromagnetic micro-forming of a stainless steel foil.