The selective laser melting (SLM) process is an additive manufacturing technique that can fabricate three-dimensional workpiece by laser scanning and sintering of designated material in powder form on a preset scanning route along a bed of powders. This process involves a moving laser heating source which causes local transient mass and heat transfer with phase change, i.e., melting and solidifying

Laser shock peening (LSP) was performed on a 316 stainless steel for microstructural and mechanical modifications. To identify the dominant factor controlling pitting corrosion resistance, a single LSP impact was performed and various characterization techniques, such as scanning electron microscopy, X-ray diffraction, transmission electron microscopy, electron backscattered diffraction, microhardness

Process parameters such as soaking time and forming temperature are critical for the isothermal warm forming performance and post-form mechanical properties. The isothermal warm forging process of AA7075-T4 aluminum alloy has been simulated through the warm compression at 180 ℃. The warm deformation schedule including fast heating and short-term initial holding is found to be advantageous for enhancing

To clarify the reaction between molten alloy and ceramic shell in the process of investment casting and control the metallurgical quality of alloy, high-temperature wetting experiments of Ni-based superalloy melt on Y2O3 ceramics with different surface microstructures were carried out. The high-temperature wettability and interfacial interactions at 1873 K between Ni-based superalloy melt and Y2O3

Analyzing and modelling the dynamic energy partition is of great significance to revealing the mechanism of belt grinding and improving grinding quality. However, there is lack of comprehensive studies on energy partition in belt grinding, especially when the dynamic characteristics are under consideration. To fill this gap, this paper analyzed the grinding energy partition from the perspective of

Ultrahard nanotwinned diamond (nt-D) is an excellent diamond material with higher hardness, better fracture toughness and thermal stability than the commonly used single crystal diamond (SCD), thus it is considered as promising tool materials applied in ultra-precision cutting. However, extremely high hardness results in the fabrication of nt-D tool more difficult than SCD because of very low machining

The preferred defect domain space for enhanced mechanical properties is a critical unknown in the selective laser melting (SLM) additive manufacturing community. This paper presents a systematic approach to relate mechanical properties and the microstructure in the keyhole and the lack of fusion domains for Ti-6Al-4 V parts. SLM laser processing conditions were modified to generate three similar amounts

This research work reports the porosity evolution during welding in the overhead position as a function of depth and working angle between electrode and plate in the underwater wet welding (UWW) process. For this purpose, different welds were simulated inside a hyperbaric chamber at depths of 10 and 50 m using three different plate angles (10, 30 and 70º) respect with the horizontal and three different

Since the inception, additive manufacturing (AM) continues to grow and change the paradigm of manufacturing for developing advanced materials. One such case is the functionally graded materials (FGM). FGM, in general, is a class of engineered materials, which is identified by a gradual change in composition and/or microstructure of one material into another over a defined volume, causing a variation

It is well known that solidification of molten metals occurs under the influence of transient unsteady phenomena, which are difficult to control in actual casting operation. Examples include buoyancy flows, natural heat convection, repeated remelting and solidification in mushy zone and solid shell at the mold interface. This paper presents the results suggesting that ultrasound waves, irradiated into

Understanding how hot cracks propagate in difficult-to-weld alloys during electron beam powder bed fusion (EBPBF) is necessary for manufacturing quality parts. The current understanding in the literature does not go into sufficient details of the mechanisms of crack propagation. The major part of this study aimed to reveal how cracks grow during EBPBF. Samples were made using EBPBF of a Co-base alloy

Thermomechanical treatment is often conducted to improve the formability and performance of high-strength aluminum alloys simultaneously. This paper presents an improved creep-age forming (CAF) processing technology that combines thermomechanical pretreatment and CAF. The proposed processing technique is expected to enhance the forming efficiency and comprehensive properties of Al–Zn–Mg–Cu alloys subjected

The aim of this research work is the adjustment of the conventional investment casting process for the single crystal casting of thin-walled near net shape specimen with cast wall thickness down to 0.4 mm. Polymer models for manufacturing of shell molds for investment casting of Ni-based superalloys were produced by additive manufacturing from three different thermosets and one thermoplastic. Temperature

The temperature rise of the working coil due to Joule heating is a very important issue in electromagnetic forming processes. A technically simple and cost-effective method was proposed to address this problem, which only needs to introduce an additional resistor in the discharge circuit. The core of this method is to alter the current waveform during the forming process by adjusting the damping coefficient

In this study, a novel low pressure sintering method for mass industrial preparing Nd-Fe-B magnets with high performance was proposed. The results indicated that the properties of magnets can be greatly enhanced via low-pressure sintering method by tuning the grain size and rich-RE phase distribution. Under the combined effects of pressure and temperature, the flowability of rich-RE liquid phase was

Laser manufacturing is widely used in modern industries for its high efficiency and accuracy. In the present work, the microstructures and mechanical properties of the laser-induced recast material on nickel-based superalloy Inconel 718 were systematically investigated. The mechanical property of the recast material was investigated with the help of the instrumented indentation technique improved by

In this study, a novel wire based plasma transferred arc (PTA)-laser hybrid additive manufacture process was proposed for deposition of large-scale titanium parts with high deposition rate and near-net shape. The optimum processing conditions, including the heat source configuration, wire feeding position, and arc-to-laser separation distance, were investigated. The benefits of using the hybrid process

In most of the machining processes, the application of surface texturing is one of the most remarkable and promising research fronts in relation to the use of tribological concepts for improving machinability. This paper aims to review the most recent articles on this theme (from 2016 to date) to assist the researchers in the state of the art of this technology, guide the forthcoming related investigations

In the automotive industry, the demand for reduced vehicle weight, improved safety and enhanced crashworthiness qualities continues to rise which introduces the need for parts with tailored properties. This demand can be met by employing tailor-welded blanks which are made of two or more types of press-hardened steels that are laser welded together and then hot-stamped to produce highly optimized parts

This research pertains to pool boiling heat transfer characteristics of Aluminum 6061 alloy surfaces that were textured using sink electrical discharge machining (EDM). Prior related work elsewhere utilized EDM as an essential means to roughen a surface or fabricate geometric features such as microchannels and micropillars to investigate boiling. As opposed to this, the present work systematically

SiC/SiC ceramic matrix composites (CMCs) offer an excellent combination of properties at high temperature such as high specific strength, chemical inertness and irradiation tolerance. Those superior properties make CMCs beneficial for use in high-temperature structural applications that are exposed to extreme environments such as aerospace and nuclear energy. However, well machining qualities can hardly

The present work analyzes the energy channelization behavior during the triplex hybrid process of ultrasonic assisted electrochemical discharge machining (UA-ECDM). In this work, a high frequency (35 kHz) low amplitude configuration of ultrasonic vibrations has been employed to investigate the ECDM process. The underlying energy channelization mechanism during the UA-ECDM process has been demonstrated

This study investigates the forming limits of cryo-rolled Ultrafine Grained (UFG) aluminium sheet for loading conditions relevant to sheet metal forming. It is shown that a combination of nano-particle strengthening with an annealing heat treatment enables the production of cryo-rolled UFG aluminium with up to 12 % higher material strength and 20 % higher formability compared with the unreinforced

Injection molding is regarded as the most significant process to manufacture high-quality polymer products. However, the molten polymer undergoes drastic variations of temperature in the cavity during injection molding, which strongly affects the dimensional accuracy, weight consistency and crystallinity of the molded products. Therefore, it is of great significance to achieve online temperature measurement

Hybrid wire arc additive-milling subtractive manufacturing (HWAAMS) is an effective method for the near net formation of complex structures by using the two processes alternately. The effects of milling width (ae) on the surface residual stress and the influence of milling thickness (t) on tensile anisotropy of the HWAAMS were studied using Al5Si aluminum alloy. The mean surface residual stress of

Enabling high precision material processing, ultrashort pulse (USP) laser beam sources are increasingly applied in the field of surface structuring. In the mold and die production, three dimensional structures with a vertical depth of a few (10–500) micrometers are created by laser ablation, resulting in a surface roughness Sa = 0.4–2 μm on the 3D structures. Because many applications require a lower

Mechanical surface modification is of great significance to the final engineering applications of particles reinforced aluminum matrix composites (PRAMCs) as structural materials. In the present study, in-situ 6 wt% TiB2/2024Al composite was surface-modified by ultrasonic rolling (UR). The surface integrity of the modified composite was comprehensively analyzed and assessed in terms of surface morphology

Tribological conditions are challenging when forming high strength aluminum alloys at elevated temperatures due to the sticking behavior of aluminum and potential material transfer to the die in the form of die pick-up. The current study examines the elevated temperature performance of several lubricants as well as a Physical Vapor Deposition (PVD) die coating, in conjunction with a 7000-series aluminum

Tube hydroforming is a well-established process in industry for producing complex shaped parts with closed cross section geometry and high geometrical accuracy. Hot-metal gas forming (HMGF) extends the conventional tube hydroforming process by a complex thermo-mechanical approach and thus potentially enables the complex processing of tubes from the relatively new class of quenching & partitioning-steels

The present investigation demonstrated the manufacturing of Al – x wt.% Zn (x = 0, 10, 20, & 30) die-casting alloys through liquid metallurgy route followed by squeezing and hot-extrusion processes. The phase analyses and microstructural evolutions were investigated by x-ray diffractometer and electron microscopes (FESEM with EDAX, EBSD, and HRTEM) respectively. The mechanical behaviour was examined

A shear modified coupled damage criterion based on continuum damage mechanics has been proposed in this study. Khan-Huang-Liang (KHL) model is implemented to predict the constitutive behavior of Ti-6Al-4 V (Ti64) alloy. A VUMAT subroutine has been developed for the damage model using a stress integration algorithm. Multiple simulations with tensile, compression and shear geometries are carried out

During friction stir lap joint welding, hooks are systematically formed at the interface of dissimilar Al2024/Ti-6Al-4V plates. Various hooks dimensions and shapes are observed according to the welding parameters (welding speed, rotational speed and double-pass). Based on digital image correlation (DIC) during tensile shear tests, it is found that hooks features govern the fracture behaviours and,

A novel ring rolling process is proposed to flexibly produce shaped rings without circumferential ring growth, potentially saving material and energy as well as reducing upstream and downstream processing requirements. In this paper, six circumferential constraint rolls are used constrain circumferential growth and enable L-shape profiles to be developed through axial material flow, via a compressive

X-ray flaw detection is a key link in the detection of internal defects in titanium alloy castings which are used for most important components in aeroengines. However, the existing manual defect detection methods from the X-ray images have common drawbacks such as unstable artificial recognition, misdetection, misjudgment, fails of quantitative analysis, huge workload, and low-quality inspection efficiency

This paper establishes a new model for predicting machined surface topography and anisotropic texture direction in peripheral milling. Unlike previous models, this model takes into account the largest number of influential factors, i.e., tool setting error (radial offset and axial tilt), static tool deflection, forced vibration, chatter vibration, and stochastic tool grinding error and wear (STGEW)

The AA6082 aluminum alloy was welded by oscillating laser-MIG hybrid welding. By using beam oscillation, the porosity can be effectively suppressed in the range of 100−300 A arc current, especially at low arc current level. Percent porosity decreased greatly with the increase of the oscillating amplitude and frequency. The threshold frequency of porosity-free at different amplitudes were achieved.

Microfluidic chips made of glass are important analytical devices for applications in biomedicine, drug development and chemical analysis. For the mass production of glass-based microfluidic chips, tungsten-made microfluidic moulds are indispensable. In this paper, a dynamic electrochemical polishing (ECP) process using a bi-layer NaOH electrolyte is proposed to uniformly polish tungsten moulds. The

Indirect laser-based surface nano- and microprocessing of optical materials demonstrate promising applications in microoptics, microfluidics and electrofluidic. The methods principle is based on the conversion of laser energy to a plasma plume, which effectively and precisely etchуы the glass backside. However, there are a lot of variable occurs during fabrication, which we discuss in this research

Droplet deposition of lead alloy to C45 steel with direct metallurgical bonding was conducted by adopting a gas tungsten arc welding (GTAW) pre-melting heat source on the surface of C45 steel substrate. It was found that a nonlinear relationship existed between the heat input of the welding arc and the feature sizes (deposition height and width) of the lead alloy deposited layers. The chemical composition

The interaction mechanism between the tool flank wear and the cutting force, in milling Ti-6Al-4V, is of significance for its further development. However, the relationship between the tool flank wear and the cutting force should be further investigated under ultrasonic-assisted milling. In this study, the longitudinal-torsional ultrasonic-assisted milling (LTUAM) Ti-6Al-4V in dry cutting was evaluated

Laser induced backside wet etching (LIBWE), a simple-setup process capable of processing transparent materials, has been studied to overcome difficulties in glass micromachining. However, LIBWE still show practical difficulty in machining various glass applications due to the crack occurrence and unprecise final geometry. This study proposes the error-compensating scan path generation method for the

A new method with digital image correlation (DIC-method) is proposed for the calibration of ductile fracture parameters and a partition optimizing method based on multi-group fracture parameters is utilized for the establishment of forming limit diagram (FLD). Both of the two methods are verified with the application of Lou-Huh ductile fracture criterion on AA7075-T6 sheet in this paper. A comparison

In injection moulding, knowledge about the cavity surface temperature and its distribution is vital for process understanding and part optimization. The measurement of cavity surface temperatures in moulding processes is often infeasible due to the harsh process environments and the limited amount of space. Therefore, a multi-layer coating system was developed for future measurement of the temperature