Bronze (Cu-Sn) coatings are widely used across various industries owing to their excellent mechanical and chemical properties. To investigate the deposition mechanism of bronze coatings fabricated via friction-assisted jet electrodeposition (FAJED) on the inner surfaces of small-diameter holes, this study developed a coupled multiphysics model that integrates the flow field, mass transfer field, and electrochemical field. Afterward, the model parameters were determined, and corresponding process experiments were conducted to validate the simulation results. Simulation results for coating thickness and composition showed average engineering errors of 7% and 22%, respectively, demonstrating good agreement with experimental data. The non-uniformity in coating thickness and elemental composition was attributed to uneven current density (electric field) and ion concentration. Experimental validation revealed that auxiliary anodes uniformized the electric field along the cavity sidewall, while the friction jet method suppressed the thickening of both the electric double layer and the diffusion layer. The synergistic effect of the auxiliary anodes and the friction jet method improved the distribution of current density and ion concentration, facilitating the successful deposition of relatively uniform bronze coatings in small-diameter holes. Overall, this study integrates simulation and experimentation, elucidates the underlying deposition mechanism, and provides a valuable reference for process optimization and uniform coating preparation for small-diameter cavities.

Plunger pairs of axial piston pumps frequently fail due to corrosion and wear. Previous studies on friction-assisted jet electrodeposition (FAJED) have primarily focused on coating preparation on the outer surfaces of planar samples, while fewer have addressed coating preparation on the inner cavities of curved structures of deep small blind hole (DSBH). To address the non-uniform distribution of electric fields and metal ions inside DSBH, this study combines FAJED with an inert auxiliary anode (IAA), effectively alleviating this key issue. Electrolytic ion replenishment (EIR) technology not only offsets the IAA’s inherent inability to replenish metal ions during electrodeposition, but also boosts coating thickness and tin content by 44 % and 380 % respectively, while extending electrolyte service life. Additionally, EIR synergizes with jet-enhanced mass transfer to reduce concentration polarization at the cathode interface, facilitating high-rate coating deposition. Thus, the integrated FAJED-IAA-EIR technology achieves the high-quality, efficient preparation of inner-surface coatings on DSBH. The optimally coated sample exhibited a coefficient of friction that was only 56.6 % of that of the uncoated sample. After 125 h of immersion in a corrosive medium, its corrosion current density was merely 0.7 % of that of the uncoated sample, corresponding to a coating protection efficiency of 99.3 %. The proposed FAJED-IAA-EIR method in this study, with high adaptability, simple process, and low cost, provides a new strategy for the efficient fabrication of high-performance coatings in DSBHs and exhibits broad application prospects.

During wire electrical discharge machining (WEDM) of titanium alloys, the combined effects of localized high discharge temperatures and intricate electrochemical reactions facilitate the rapid formation of an oxide film on the machined surface. This oxide layer induces thin-film interference, leading to visible surface coloration that distinctly differs from the substrate's original appearance—a phenomenon referred to as titanium alloy coloration. To address this issue, an auxiliary electrode was introduced to mitigate the oxidation reaction by actively controlling the ionic interactions between the dielectric fluid and the workpiece. The suppression mechanism was examined through color difference measurements, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Furthermore, single-factor experiments were conducted to systematically evaluate the effects of critical process parameters—auxiliary voltage, Auxiliary Distance (Distance between Auxiliary Electrode and Workpiece), and tracking frequency—on the material removal rate (MRR), surface roughness (Ra), and oxide layer thickness. Results indicate that the auxiliary electrode markedly reduces oxide thickness by directing the migration of ions within the dielectric, thereby producing a surface morphology that closely resembles the untreated substrate. This study validates the efficacy of the auxiliary electrode approach in minimizing surface coloration during WEDM and offers an experimental foundation for achieving non-coloring precision machining of titanium alloys.

Exploring methods to enhance precision during laser powder bed fusion (LPBF) based directed manufacturing is highly meaningful. However, the origin of defects remains unclear during the small-layer-thickness LPBF process. This study investigates the process of LPBF with a thin layer thickness of 10 & micro;m. It focuses on two aspects: first, the influence of different dimensional parameters on distinct dimensional interfaces (At different depths, sequentially divide into the first interface, second interface, third interface, and fourth interface), specifically, the effects of path energy input and scanning hatch space on the morphology of the top interface and the porosity of the layer-to-layer interface. Second, it examines the relationship between different dimensional interfaces, namely, the connection between the morphology of the top interface (first interface) and the porosity of the layer-to-layer interface (third interface). Results indicate that at a path energy input of (9 +/- 0.5) & times; 10-5 J/& micro;m and a hatch space of (60 +/- 5) & micro;m, the melt at the top interface flows in parallel, the melt path shifts downward, the melt at the layer-to-layer interface flows forward; the move orientation of the molten pool at the top interface are identical to that at the layer-to-layer interface, indicating consistent melt flow behavior. The melt at the layer-to-layer interface is fully melted, with fewer pores at the boundaries of the upper and lower melt paths. By analyzing the melt morphology at multi-layer interfaces, the evolution process of LPBF in titanium-based 210016, China. composites can be clarified. Furthermore, interlayer porosity can be optimized based on the numerical model of layer-to-layer interface.

During reciprocating wire electrical discharge machining (WEDM) of variable-thickness materials, conventional fixed-threshold servo control systems cannot accurately assess the inter-electrode machining state, which leads to lower cutting efficiency and degraded surface quality. To address this problem, we propose an adaptive servo control strategy with a tunable threshold, which evaluates the ratio of breakdown delay time to total pulse duration. The system acquires inter-electrode voltage in real time, calculates the ratio of breakdown delay duration to the corresponding total pulse duration within a unit time to identify the machining state, and dynamically adjusts the threshold voltage through a binary-weighted resistor divider network. This mechanism keeps the ratio within a predefined optimal range. Experimental results show that, compared with the fixed-threshold method, the proposed adaptive control system improves overall machining stability for variable-thickness workpieces, increases efficiency by 8

Bronze, as a solid self-lubricating material, is widely used in various frictional applications. However, under increasingly common high-frequency and high-load conditions, particularly in the absence of lubricants, bronze layers are prone to rapid wear. Incorporating MoS2 particles to fabricate solid self-lubricating composite coatings is considered a promising approach to improve overall performance in harsh environments. In this study, a friction-assisted jet electrodeposition process is employed to fabricate Cu-Sn-MoS2 composite coatings. This technique enhances particle embedding and surface leveling, producing uniform and dense coatings with significantly improved tribological performance. The methodological framework of this study involves the fabrication of Cu-Sn-MoS2 composite coatings via friction-assisted jet electrodeposition, followed by systematic characterization of their surface morphology, microhardness, adhesion, and tribological behavior. The results show that a MoS2 content of 5 g/L provides a uniform and compact surface with fine grains, sufficient microhardness and adhesion strength, and a continuous lubricating film formed during wear. The wear mechanism was revealed to explain why the Cu-Sn-MoS2 coating exhibited a strong performance in mechanical properties and wear resistance. This content achieves the lowest friction coefficient and the best wear resistance among all tested compositions.

Wire bow in diamond wire sawing leads to trajectory deviation, which significantly reduces the geometric accuracy of hard and brittle materials. Existing vision-based approaches focus on monitoring the slicing process and typically rely on high-speed cameras. However, few practical solutions exist for profile cutting, where the wire bow spatially varies in real time. This study proposes a low-cost, vision-based servo feed control system for regulating the wire-bow angle in a reciprocating single-wire saw. A standard camera is used for straight cutting, while two cameras independently operate for profile cutting. An event-triggered pause/resume strategy based on dual wire-bow-angle thresholds of 0.5° (lower) and 1.0° (upper) is implemented using a National Instruments LabVIEW-based host computer and an embedded controller. The system successfully maintains the upper wire-bow angle within the predefined range throughout the cutting trials. Comparative experiments on soda-lime silicate glass for straight and octagonal profiles are then conducted. The obtained results show that in straight cutting, the sawn length and surface flatness accuracy are markedly increased compared with the conventional process without vision-servo control. For octagonal cutting, the mean errors of opposite-side distance decreased by 18.4

Inert anodes provide a continuous and stable interelectrode electric field with a non-deforming surface during the process of electroplating. However, the concentration of cations is decreased with the reaction in inert anode electrodeposition system, which is replenished by metallic anode in soluble anodes electrodeposition. In this work, a strategy was proposed that the electrodeposition with inert anode was assisted by electrolysis method with anion exchange membrane (AEM), which has ability to selectively exchange anions in the electrolyte. Nickel coatings were fabricated by direct current electrodeposition with AEM-electrolysis assistance, aiming to assess the effect of the AEM-integrated electrolysis approach. The surface morphology, chemical composition distribution, grain structure, hardness, and corrosion behavior were investigated by characterization. Cyclic Voltammetry technology was applied to quantitively analyses the concentration of Ni2+, in the Watts bath after experiments. The results showed that the AEM-electrolysis method consumed only 22.7% of the Ni2+ in the original solution after 10-hour electrodeposition. Moreover, the surface quality, mechanical properties and corrosion resistance were improved. It is practical to improve the coating quality and extend the life of electrolyte in electrodeposition with inert anode via AEM-electrolysis method.

4H-SiC is a typical difficult-to-machine semiconductor due to its high hardness and anisotropy. Conventional abrasive machining is limited by subsurface damage (SSD) and tool wear. Thermally assisted machining offers advantages, but achieving thermal-mechanical coupling remains experimentally challenging. This study established a molecular dynamics (MD) model featuring synchronized contact between the heating zone and abrasive grains—simulated along the [ 1210 ] crystal direction. The surface thermal power densities (Ps) were varied to investigate damage evolution, chip-debris morphology, machining forces, sliding friction coefficient (μ), dislocations, and SSD depth. Compared with conventional abrasive machining, at a critical Ps of 12.0 × 1011 W/cm2, μ, weighted mean of von Mises stress ( σ_vm ), and SSD depth decrease by 49.0, 28.3, and 67.6 σ_vm reduction in the deformation zone, which promotes plastic flow and surface amorphization. Energy dissipation is confined to the near-surface region, suppressing SSD propagation. This study provides atomic-scale insights for optimizing thermally assisted parameters to minimize SSD.

Relatively low efficiency of selective laser melting (SLM) in general molding strategy, it is extremely important to seek efficient forming strategy to make fast and precise manufacturing of Ti-based alloy. However, it is found that defects such as porosity and cracks are easily generated during the fast and precise forming process, especially under the ultra-high powder layer thickness (more than 100 mu m) and the corresponding forming strategy. In this paper, the effect of energy input on the melt pool morphology is investigated at different powder layer thickness in SLM, 30 mu m for the low layer thickness (10 mu m-40 mu m) and 90 mu m for the high layer thickness (70 mu m-100 mu m), and melt pool simulations are performed to verify its evolution. Meanwhile, the effect of hatch space on the melt path morphology is investigated at the same powder layer thickness in SLM, 90 mu m for the high layer thickness, and melt path simulations are performed to verify its evolution. The results show that high energy input is a prerequisite for high layer thickness forming, it mainly increases the melt velocity in the melt depth direction, which enhances the melting region by expanding the melt pool morphology, but causes uneven melting path and pore defects. Hatch space has a moderating effect on high energy input, it mainly increases the melt velocity in the melt width direction, which uniform the volume distribution by changing the melt path morphology, reduces the uneven melting path and porosity defects. Finally, the coupling of energy input and hatch space suppress melt pool and melt path defects, and make high layer thickness SLM forming of Ti-based alloy with high quality.

I n the process of selective laser melting (SLM) for precision manufacturing, increasing the powder layer thickness can directly improve the additive manufacturing rate. But the sources of defects in large powder layer thickness are complex and numerous, especially uneven fusion and pores. For 90 µm large powder thickness SLM, it is investigated that for the corrected surface energy density, the effect of line energy density and field width on the top interface morphology and interlayer interface pores. For SLM with a large layer thickness of 90 µm, this study investigates the effect of corrected surface energy density on melt morphology in SLM using numerical simulations, especially the effect of line energy density and field width on the top interface morphology and interlayer interface pores. It investigates the variations of melt morphology at different interfaces, as well as the correlation between the top interface (first interface) morphology and the interlayer interface (third interface) pores. The results show that at a line energy density of 0.30 (+ 0.05) J/mm and a field width of 0.125 (+ 0.015) mm, the melt at the top interface flows backward, the melt at the interlayer interface flows backward, and the melt flow direction at the top interface is the same as that at the interlayer interface so that there is consistency in the melt flow. The melt at the interlayer interface is sufficiently fused, and there are fewer pores at the boundaries of the top and bottom melt channels; the melt at the top interface is sufficiently fused, and there are fewer pores at the boundaries of the neighboring melt channels. Based on the multi-interface numerical model, it can help to reveal the evolution of interface morphology and interface porosity and predict the interlayer interface porosity based on the interlayer interface melt morphology.

Atomization ablation machining is an electrical discharge machining (EDM) method with enhanced machining efficiency. This method introduces oxygen between the electrodes, causing oxygen and activated metals to burn violently under spark induction. When this method is used to machine aluminum matrix silicon carbide materials, oxygen will oxidize the aluminum matrix to form a non-conductive oxide film. This generated film affects the machining stability and impacts the material removal rate (MRR), electrode wear, and machining surface quality. To address these issues, this study proposed a reciprocating vibration multi-channel atomization ablation-electrolysis-chemical composite machining method. This proposed method enhanced chip removal between the electrodes through the reciprocating vibration of the electrode to maintain stable machining. A multi-channel electrode was used to disperse the discharge energy to obtain better machining surface quality while maintaining efficient machining. In addition, a sodium carbonate solution was used as the atomization medium. To maintain the stability of machining, the chemical reaction between sodium carbonate and aluminum oxide at high temperatures was used to remove the oxide layer. Finally, the recast layer was removed through electrolysis. Under the same electrical parameters, the MRR of the composite machining method was 540% of that of reciprocating vibration EDM, 180% of that of reciprocating vibration atomization ablation machining, and 140% of that of reciprocating vibration multi-channel atomization ablation machining. Its surface roughness (Ra) was reduced by 62.38%, 65.29%, and 32.05% compared with these three methods, respectively. Moreover, the composite machining method achieved relative electrode wear rates (REWR) that were approximately 10.70%, 13.73%, and 27.65% of those of other methods.

The high-volume-fraction SiC particle-reinforced aluminum matrix composites (SiCp/Al) machined by high-speed wire electrical discharge machining (HS-WEDM) can only cut under low energy, and it is easy to break the wire when cutting under high energy. The causes of the problem are analyzed. According to the analysis, it is considered that when cutting SiCp/Al composites, the presence of aluminum oxide and silicon dioxide insulating particles on the wire electrode surface leads to a gap discharge state between the wire electrode and the conductive block. Additionally, the contact angle between the wire electrode and the conductive block is small, resulting in unstable sliding contact. With an increase in discharge energy, the high-speed and vibrating wire electrode becomes susceptible to wire breakage. To address this problem, an open-guide-wheel power supply method is proposed. This method increases the contact area and angle between the wire electrode and the guide wheel, achieving a stable power supply through rolling contact and effectively suppressing the electric corrosion effect. Additionally, the open structure resolves the issue of the power supply device burning out, which occurs with the traditional closed structure. The experimental results show that using the open-guide-wheel power supply method achieves persistent and efficient cutting of 70-mm 55vol.

Manufacturing efficiency and precision are equally important. A reasonable balance between efficiency and precision is conducive to the sustainable manufacturing of specific alloys. The powder layer thickness is a direct determinant of the alloy forming results. When the powder layer thickness and energy density are high, the forming precision of the alloy is relatively low. Conversely, when the powder layer thickness and energy density are low, the forming efficiency of the alloy decreases. This study investigates, the effects of variable layer thickness scanning on surface morphology and internal porosity under the constant volumetric energy density. It also analyzes, the correlation between surface morphology and internal porosity under different cyclic layer thicknesses. The results indicate that for high layer thickness selective laser melting (SLM), variable layer thickness scanning plays a significant role in adjusting surface morphology, and thereby inhibiting the formation of internal porosity. When the average volumetric energy density is 3.3 x 1010 J/m3, and the cyclic powder layer thickness ranges from 90 mu m to 30 mu m. Under the condition of cyclic powder layer thickness, the irregular melt tracks are uniformly melted without generating additional porosity, similarly, the splashing of powder and melt is also uniformly melted without generating additional porosity.

Improper parameters during WEDM processing of titanium alloys can cause surface color changes and affect material removal rate (MRR) and surface roughness (Ra). By using the principle of thin film interference color development, it was found that TI-6AL-4V undergoes surface oxidation and forms a layer of titanium oxide film under the influence of high temperature between electrodes and electrolysis during the processing, resulting in different visual colors. This article conducts process parameter optimization experiments through the design of L16 (44) orthogonal experimental method. The main optimization indicators are titanium oxide film thickness (Ox), MRR, and Ra, and the process parameters are the number of power tubes (PTs), pulse width (Ton), pulse gap (Toff), and tracking parameters (TPs). Using the signal-to-noise ratio analysis method, the influence of various process parameters on different optimization indicators and the optimal combination of single objective processing parameters were studied and experimentally verified. The results indicate that the minimum Ox can be obtained when Ton is 12, Toff is 8, PT is 4, and TP is 2. When Ton is 3, Toff is 2, PT is 1, and TP is 150, the minimum Ra can be obtained. When Ton is 9, Toff is 2, PT is 2, and TP is 2, the maximum MRR can be obtained.

Owing to low machining efficiency, poor machining accuracy, and surface quality in traditional electrical discharge machining (EDM) of TC4 titanium alloy holes, an EDM trepanning method was developed using a deionized water medium and a flushing liquid in tube electrodes (denoted by EDM-TFD). Several experiments and research mechanisms were conducted on EDM-TFD. Compared with traditional EDM, ED milling, and EDM trepanning, EDM-TFD featured increased hole machining efficiency by more than five times, improved machining taper by more than 57%, and improved surface quality by more than 40%. The optimal processing technology was determined through process experiments using copper tube electrodes, a flushing liquid with a speed of 2 m/s, pulse width ( T on ) of 150 μs, pulse interval ( T off ) of 150 μs, and peak current ( I p ) of 15 A. Under the optimized process, the hole exhibited a feed rate of 1.1 mm/min, machining efficiency of 38 mm 3 /min, machining taper of 40 μm, and surface roughness of 5.2 μm.

In order to minimize the subsequent cutting of aerospace structural parts of difficult-to-machine materials such as high-temperature alloys and to shorten the machining cycle, this paper proposes a machining method that uses electrical discharge machining (EDM) for initial hollowing. The method adopts a U-shaped fine copper tube electrode, with an open row of holes on this electrode in the processing area, and uses deionized water as a working medium to take advantage of the jet effect. The copper tube electrode in the processing area takes part in reciprocating movement to complete the EDM hollowing processing. Three types of feeds—linear feed, S-shaped feed, and lateral reciprocating feed—were designed for the copper tube electrodes. The material removal rate and tool wear ratio of the three feeds are compared and the etching mechanism is analyzed. It is found that the transverse reciprocating feed has the highest material removal rate, 29.99 mm3/min, which is 255

10CrNi3Mo alloy steel has the characteristics of high hardness and wear resistance, and is widely used in aircraft and spacecraft, shipbuilding and so on. However, its conventional processing method has high tool loss. Wire Electrical Discharge Machining (WEDM) technology is based on electrode pulse discharge to corrode materials. There is no direct contact between the tool and the workpiece, so it is suitable for processing materials with complex shapes, such as high hardness and high brittleness. The focus of this study is to investigate the effects of different electrical parameters such as pulse width, pulse gap, current, and wire feeding speed on the recast layer thickness (RCL) and surface roughness (SR) of 10CrNi3Mo alloy steel processed by wire discharge machining using orthogonal experiments. The gray correlation method was used to optimize the above two process indicators, and seeking optimal processing parameters. The optimized recast layer thickness was 8.65 mu m. The surface roughness is 1.932 mu m. Achieve expected goals.

This study investigated the impact of varying atomization amounts on composite machining involving both atomized electrical discharge ablation machining and electrochemical machining (EDAM-ECM). Additionally, this study examined the effects of different atomization amounts on the material removal rate, relative electrode wear rate, processing waveforms, surface roughness, surface morphology and elements, and the EDAM-to-ECM ratio. Moreover, a theoretical model for describing the material removal process in composite processing was developed. Furthermore, the effect of the ECM ratio on the processing results was quantitatively analyzed through the integration of statistical circuits with a formula for calculating recast layer thickness. The model was used to predict and select the optimal atomization amounts required to achieve recast layer removal during processing. The results revealed that at an atomization amount of 200 mL/min, 16.7% of the total material removal was attributable to ECM, indicating the successful removal of the recast layer. At this atomization amount, the fabricated sample maintained a machining precision of 0.02 mm.

As a kind of metal matrix composites, silicon carbide particulate reinforced aluminum alloy composites (SiCp/Al) have been widely applied in numerous fields. However, it is still difficult to process this composite material with electrical discharge machining (EDM) at present. To address this problem, this study introduces a novel rotary electrochemical discharge - chemical composite machining (RECDM-CM) method. This method uses rotating electrodes and workpieces to improve the flushing effect of working medium and utilizes the electrolysis to reduce the recast layer thickness. The chemical reaction between sodium carbonate (Na2CO3) and aluminum oxide (Al2O3) at high temperatures is used to remove the non-conductive Al2O3 in this composite machining. Rotary electrochemical discharge - chemical composite machining is used to process silicon carbide particulate reinforced AA2009 aluminum alloy composites with the silicon carbide volume fraction of 55%. The experimental results reveal that the material removal rate (MRR) of rotary electrochemical discharge - chemical composite machining is 5.2 times that of rotary electrical discharge machining, and its relative tool wear rate (RTWR) is 37.42% of rotary electrical discharge machining. The recast layer thickness is reduced to less than 13 mu m via rotary electrochemical discharge - chemical composite machining.