Recyclable electronics are important in green manufacturing and sustainable development, but in infancy, printing strategies still need more exploration and improvement. Metal drop-on-demand (DOD) printing is an ideal candidate for fabricating recyclable circuits, owing to its advantage of inherent direct recyclable feedstocks. Liquid metals with melting points at room temperature have been utilized

The influence of copper (Cu) on fluidity and hot tearing susceptibility (HTS) of Mg-7Zn-xCu (x = 0, 1, 2, 3) ternary alloys was studied by experimental investigation and simulation assessment. The experimental investigations were carried out using bespoke fluidity and “T-shaped” hot tearing test molds. The microstructure and morphology were characterized by scanning electron microscopy system equipped

The altered microstructure during machining process had an inverse influence on materials behavior, machining forces and surface integrity. Thus, a constitutive model which builds the response of flow stress on microstructure evolution is gaining rising interest. Based on Johnson-Cook model, a modified constitutive model coupled with microstructure evolution incremental model for machining of Ti-6Al-4V

In this study, the austenite transformation behaviour in a medium-Mn (MMn) steel is investigated during heat treatments that replicate those occurring in low-temperature hot stamping (LTHS), with the aim of better understanding this behaviour to optimise heat-treatment design. The austenitisation behaviour and critical phase transformation temperatures during the LTHS heating process and their dependence

Improving the machining quality of Aramid Fiber Reinforced Plastics (AFRPs) is of great significance for industrial manufacturing in various fields but it is challenging. Existing conventional machining (CM) generally brings about subsurface damage and severe burr. In this study, the longitudinal-torsional ultrasonic vibration milling (LTUVM) was applied to AFRPs machining to solve these issues. Burr

Diamond/Al composites have been considered as the new generation of thermal management material. The critical challenge is that Al4C3 with deteriorating properties is easily generated at the interface of composites by conventional powder metallurgy and infiltration processes. This paper presents an independently developed liquid-solid separation (LSS) technology for fabricating diamond/Al composites

The preparation of hierarchical microstructured surfaces to obtain different wettability has been studied in both academy and industry. Polytetrafluoroethylene (PTFE) is an ideal material for preparing superhydrophobic surface due to its ultra-low surface energy. However, it is still a challenge to prepare hierarchical structure on the surface of PTFE. In this paper, PTFE films with hierarchical structure

This paper investigates the effect of ultrasonic surface rolling processing (USRP) on the surface integrity, microstructure, hardness, and residual stress of selective electron beam melted (SEBMed) Ti6Al4V with as-built surface. Results show that the semi-melted powder and melting pool ridges are flattened due to the ultrasonic impact and static load, as well as surface defects, such as ‘stairs’ and

This paper presents a study of fabricating micro-dimples with desired morphology characteristics using micro-abrasive jet machining. Experiments are conducted under different processing conditions so that blasted dimples with various sizes and geometries could be obtained and analysed. The results indicated that among all the processing factors used in this study, changing processing time and air pressure

Due to the weak rigidity of flexible thin-walled part and tool, deformation inevitably occurs under the action of a cutting force in the flank milling of thin-walled parts, resulting in reductions of the machining accuracy and efficiency. To solve the above problem, a force-induced deformation prediction model based on the static substructure method and a flexible error compensation strategy for the

This work investigates a unique technique to join aluminum (Al) and magnesium (Mg) alloys to carbon fiber reinforced polymer (CFRP) composites without the use of adhesives or mechanical fasteners. The joints were made using an overcasting technique where the molten alloys were cast around the polymer composites using high pressure die casting method. Rapid cooling during casting allowed the composite

A novel material tracing technology was proposed using ER2319 aluminium alloy welding wire as the tracer material to study the material flow behaviour at different positions of friction stir welded 6061-T6 aluminium alloy joint. Having been influenced by temperature and driving force of the tool, the displacement of all the tracer materials deposited behind the original position during welding decreased

Electrolyte jet machining (EJM) is an innovative form of electrochemical machining (ECM) with excellent machining flexibility and accuracy. Recently, the nozzle inclination is introduced into EJM to further expand its machinability. In this work, to clearly reveal the mechanism behind this EJM process, a three-dimensional (3-D) multiphysics model of the stationary EJM process accounting for two-phase

Manganese sulfide (MnS) is an important kind of non-metallic inclusion in steel which precipitates at the final stage of solidification and greatly affects the properties of steels. Plenty models have been developed to simulate the dynamics of MnS during solidification, while few considered its effects on macrosegregation formation in return. Here a four-phase model has been developed to couple the

Blade root with a special fir-tree shape is a critical connection part in an aero-engine. This part has high requirements on the surface finish and geometrical accuracy. At present, the tangential ultrasonic vibration-assisted profile grinding (UVAPG) is an effective method for machining the blade roots. During UVAPG, the wheel wear degrades the surface finish and geometrical accuracy. However, the

Milling chatter occurs as undesired vibration in the cutting process, imposing negative effects on the tool’s life, the quality of surface finishes and the limitation of machining efficiency. In this paper, a discrete output feedback robust controller based on linear matrix inequality (LMI) is developed for the chatter suppression, with an electromagnetic actuator applying the needed active control

Dissimilar joints of copper and aluminium alloy were generated by electric current assisted ultrasonic welding (EUSW). The microstructure characteristics and mechanical properties of Cu/Al EUSW joints were systematically investigated. The electric current promoted the plastic flow at the welding interface. The intermetallic thickness increased with electric current. The microstructure characteristics

Pack rolling is an effective process for manufacturing Ti-6Al-4V products, especially thin sheets; however, it tends to cause surface defects. Surface ridging is the most significant surface defect produced during the pack rolling of thin sheets. Hence, in this study, the effects of pack-rolling conditions on the origin of surface ridging on Ti–6Al–4V alloy surfaces were investigated using experimental

Metal additive manufacturing has been widely used in many fields. It is important to realize the support-free deposition of metal parts since the supporting structure is hard to remove. Some of the existing support-free methods are complicated by generating curved layers, which may also cause defects between layers. This paper presents a support-free wire and arc additive manufacturing (WAAM) method

The cooling efficiency of aluminum die-casting molds is critical to prevent soldering, extend mold life and manufacture high quality castings. In this paper, we discuss a method of inserting a pure copper (Cu) lining using explosive expansion bonding process. A pure Cu bush was inserted into a cooling channel of die casting mold and bonded to the inner surface of the cooling channel through explosive

Local post weld heat treatment (PWHT) is usually employed in the field fabrication of large-sized 9% Cr heat resistant steel welded components, such as power plant boilers. Temperature field in local PWHT plays critical roles in both achieving PWHT purposes and avoiding detrimental effects of local heating. The objective of this research is to quantify the effects of local PWHT parameters and pipe

Three combined-extrusion techniques of second extrusion, die upsetting and extrusion, and cyclic extrusion and compression were used to fabricate three typical {0002} basal textures of fiber texture, dispersed texture and inclined texture, respectively, in the fine-grained ZK61 magnesium alloy. The tension-compression asymmetries were compared and the texture influence on asymmetry mechanical response

This work aims at modelling the mechanical behaviour of inorganically-bound core materials. In this article, the mechanical material parameters for inorganically-bound core materials for various binder amounts and temperatures are determined. Specifically, the influence of the binder amount on the elastic properties and the Mohr–Coulomb parameters of the sand cores is studied. Furthermore, the hardening

Predicting the ductile fracture in aluminum alloys during hot deformation is important for controlling product quality. To this end, this paper proposes an improved damage-coupled viscoplastic model for predicting the ductile fracture in aluminum alloys at high temperatures. For this model, a dislocation-based viscoplastic model is adopted, and a novel high-temperature damage model is further proposed

Accurate prediction of the friction-mediated interaction between workpieces in ultrasonic welding requires nonlinear multi-physical models. Local contact points that are in slip receive a heat flux from friction, which raises the local temperature and therefore, changes the local material stiffness and local stresses. These local changes affect the contact status and the overall dynamics. The effects

This article proposes a new method to classify the decoring behaviour of different cast-in sand cores for light metal casting. Sand cores are in use to realise hollow structures in casting parts. More and more inorganically bound sand cores are used due to environmental requirements, which, in contrast to organically bound sand cores, do not disintegrate during the casting process. The inorganically

We investigated the effect of ultrasonic shot peening on the surface integrity and fatigue properties of single-crystal superalloys. The results show that ultrasonic shot peening significantly reduces the surface roughness of single-crystal specimens and improves surface finishing. The surface hardness increases by 49 %, reaching more than HV660. At the same time, the microstructural analysis illustrates

Thin-walled cylindrical parts with longitudinal inner ribs (CPLIRs) made of magnesium alloys are one of the most promising lightweight components. Flow forming is an effective technology to realize the integrated manufacturing of thin-walled CPLIRs. However, due to the complicated material flow and narrow temperature window, defects like insufficient filling at the rib groove and concavity of the back

Welded joints of molybdenum (Mo) and Mo alloy have high brittleness and low strength, which seriously limit its application as structural materials. In this study, Nitrogen (N) is used to strengthen the fusion zone (FZ) in the Mo laser beam welding joints and N is added into the FZ during a laser gas alloying process. The XPS and SEM confirm that many Mo2N phase were distributed on the surface of the

In this study, through the comparison of the microstructure evolution between composites and matrix alloy, the effects of nano-sized SiC particles (i.e. nano-SiCp) on solution behavior and properties of 1 wt.% nano-SiCp/Al-Cu composites were investigated for the first time. Results indicate that different from the traditional solution treatment process of Al-Cu matrix alloy, due to the hindering effect

In this work, Al-5Cu and TiC/Al-5Cu strips were fabricated by vertical-type twin-roll casting (TRC), and the effects of TiC nanoparticles on the Al-Cu strips were investigated. The minor addition of TiC nanoparticles refined the grain structure, increased the Cu concentration in the α-Al dendrites and effectively mitigated the center macro-segregation of the as-cast strip, which could be due to the

The self-cleaning effect of linear friction welding (LFW) is believed to be a crucial means to remove surface contaminants for achieving a satisfactory property of the resultant joints. To systematically investigate the self-cleaning process, a fully-coupled computational model was established based on an integrated approach considering dual plastic bodies for simulating the LFW of a typical Ni-based

Producing load-adapted and functionally integrated components by flexible and resource efficient processes has gained importance within industries like the automotive sector in recent years. A promising new class of processes that enables a local adaption of the sheet thickness is Sheet-Bulk Metal Forming (SBMF). While the incremental procedure (iSBMF) only requires a moderate forming force, forming

In this study, a novel molten-salt-assisted in-situ synthesis method was developed to cast copper (Cu) containing uniformly distributed tungsten (W) nanoparticles using tungsten oxide (WO3) microparticles as the precursor. With WO3 microparticles dissolved by molten KAlF4 and reduced by molten aluminum (Al), W nanoparticles were formed in the Cu matrix and their sizes were significantly reduced compared

With the advantages of electrochemical milling (ECM) and conventional milling (CM), mechano-electrochemical milling (MECM) is effective for shaping titanium alloys. However, previous research failed to clarify the mechanism for material removal in MECM, seriously limiting its further application. This work focuses on an in-depth investigation of the material removal mechanism in the MECM of TC4 titanium

To improve surface roughness of components without altering geometrical dimensions, polishing operations are commonly used. These operations may be time-consuming and expensive. Thus, the prediction of polished surface quality is a key issue to reduce the cost of these operations. Resulting surface quality of polishing operations is the outcome of a large number of local cutting phenomena (grains-material)

Titanium alloys have been widely used in many high-end components and parts in various fields, and the excellent surface quality of titanium alloys is highly required. In this study, chemical mechanical polishing (CMP) was used as an effective surface processing technology, and the effects of pH and H2O2 on the CMP performance of titanium alloys TA2 (pure titanium) and TC4 (Ti-6Al-4 V) were thoroughly

Abstract For calibrating sheet metal hardening and anisotropic constitutive models, the bulge test has proven to be an invaluable tool. In recent studies, the analysis of the test has been considerably improved by using Digital Image Correlation. Despite the progress achieved in the analysis of the measured data, based on membrane hypotheses it is still necessary to use large bulge diameter to sheet

Abstract Recently, binder jetting additive manufacturing (BJAM) was used to manufacture complex metal parts in an economical and large-scale way. However, the usage of resin to bond metal powder renders as-printed green parts with low strength, which is potential to cause the structural damages of final parts during post treatments. To overcome the intractable problem, a self-developed binder mainly