Search Results (213)

Novel steel composite metal foams (CMFs) are lightweight materials made from stainless-steel hollow spheres, with entrapped air suspended within the stainless-steel matrix. In this work, the performance of CMF-core front rails, containing steel CMF within an aluminum 6061 alloy double tube, is compared against rectangular high-strength low-alloy (HSLA) 350 steel and double-octagon aluminum 6061 alloy front rails of equivalent masses and lengths. Explicit finite element models of different front rails are subjected to frontal impact with entrapped air within the CMF core modeled using the pneumatic fluid cavity technique. The inclusion of a steel CMF-core within the double-tube structure results in plateauing vehicle deceleration instead of pulsating behavior observed during the buckling of tube-only structures. CMFs containing pressurized air and core–tube interactions enhance the compressive resistance of front rails to prevent localized bucking. The CMF-core front rail increases the accident velocity required to exceed the critical accident severity and head injury criterion (HIC) by 33.73% and 39.50%, respectively, when compared to an equivalent double-octagon front rail and by 31.93% and 48.24%, respectively, when compared to an equivalent rectangular front rail. The research demonstrates that utilizing novel energy-absorbing steel CMFs within automotive front rail structures helps improve occupant safety for crashworthiness applications. Full article

Aluminum alloy 6061 is widely used in the industrial field, but its poor corrosion resistance has a significant impact on the reliability of equipment components. To address the corrosion resistance issue of 6061 aluminum alloy, a novel Ti-Zr-V conversion coating was prepared on its surface in this study, and the conversion parameters were optimized. The morphology, element distribution and content, composition of compounds, and corrosion resistance of the prepared Ti-Zr-V conversion coating were comprehensively analyzed and evaluated using scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, copper sulfate spot test, and electrochemical experiments. The research results showed that the conversion parameters had a significant impact on the corrosion resistance of the conversion coating. The optimal conversion parameters were a pH value of 4.5 and a conversion time of 5 min, with the optimal addition amount of the auxiliary film former NaVO₃ being 0.6 g/L. Under these conditions, the Ti-Zr-V conversion coating prepared was relatively dense, with fewer grooves, the longest spot resistance time, and the best corrosion resistance. Its surface mainly consisted of titanium dioxide, zirconium dioxide, vanadium pentoxide, V₂O₃, aluminum oxide, and a small amount of fluoride compounds. Electrochemical analysis also demonstrated that the corrosion rate of TiZrVCC decreased by approximately 87.12% compared to the aluminum alloy 6061 substrate, providing a theoretical basis and technical support for the further promotion and use of aluminum alloy. Full article

Non-contact metric inspection of metallic circular holes is essential for assembly quality control, yet remains difficult on reflective machined surfaces, where depth scale, stripe radiometry, and contour geometry degrade simultaneously. Pure monocular two-dimensional vision localizes hole boundaries efficiently but cannot resolve metric depth; multi-camera three-dimensional systems remove this ambiguity but with a heavier hardware and calibration cost; and conventional structured-light pipelines often improve stripe extraction or circle fitting in isolation, leaving the overall measurement chain fragile when reflection and edge defects co-occur. This paper proposes a monocular structured-light framework that treats sensing geometry, radiometric stripe reliability, and outlier-robust hole estimation as one coupled measurement chain. A single calibrated industrial camera is combined with an obliquely projected line laser to fuse top-view contour observation with light-plane-constrained depth recovery. Multi-exposure high-dynamic-range (HDR) fusion, adaptive Gaussian regularization, and distance-weighted gray-centroid refinement stabilize sub-pixel stripe centerlines under local saturation and uneven illumination, while geometry-aware contour screening and probabilistic multi-stage RANSAC fitting suppress burr-induced outliers during circle-parameter estimation. Experiments were conducted on a steel bolt-hole workpiece and a 6061 aluminum-alloy plate containing five holes with nominal diameters spanning approximately 30–78 mm. The original steel workpiece was evaluated for its diameter and two datum-related center-position quantities, while the five-hole plate was evaluated through three repeated optical diameter measurements and independent CMM references. For the five aluminum-alloy holes, the mean optical–CMM diameter differences ranged from 0.006 to 0.218 mm, with an average absolute difference of 0.096 mm. The results establish feasibility over the tested workpieces and calibrated measurement volume rather than generalization to arbitrary hole geometries, materials, or surface conditions. Full article

This work provides a comprehensive review of the development and current research status of micro-arc oxidation (MAO) coatings on 6061 aluminum alloy. It presents research findings on the enhancement of wear resistance, corrosion resistance, and other functional properties (e.g., hydrophobicity, thermal control performance, and electrical insulation) using three main strategies: insitu growth via electrolyte composition modification or electrical parameter adjustment, incorporation of nanoparticles into the electrolyte, and hybrid processes combining MAO with other surface treatment techniques (e.g., pre-/post-treatments). The performance of coatings obtained under different strategies is summarized, and a prospective outlook on future development trends in this field is offered. Full article

High-speed machining of complex freeform geometries faces fundamental challenges in balancing computational efficiency, kinematic constraints, and precision, particularly in high-curvature regions where traditional interpolation methods suffer from geometric errors and jerk-induced vibrations. This study presents a Galerkin-NURBS interpolation framework that integrates Galerkin projection to optimize NURBS parameterization, minimizing geometric approximation error, and couples it with a jerk-limited S-curve trajectory planning algorithm that enforces $C^3$ continuity while respecting feedrate, acceleration, and jerk constraints. Numerical simulations and machining experiments were conducted on butterfly-shaped and horse-shaped curves using a five-axis CNC machine equipped with rotary/linear encoders and validated via profilometer-based surface roughness measurements. The proposed method achieved a 32.9% reduction in processing time (3.091 s) compared to the CQSF method (4.61 s) and a 35.1% reduction in interpolation steps relative to FSRC. Surface roughness ($R_a$) values ranged from 0.1271 μm to 0.2009 μm, with most measurements compliant with ISO 21920-1:2021; the maximum value (0.2009 μm) represents the upper bound of the standard’s high-precision threshold for aluminum alloy 6061. These findings demonstrate that the proposed framework significantly improves machining efficiency and surface quality while maintaining geometric fidelity, making it suitable for precision manufacturing applications where sensor-guided process optimization is critical. Full article

During aviation operations, low temperatures can cause fuel freezing and icing on 6061 aluminum fuel lines, threatening flight safety. To mitigate this, a surface treatment combining FeCl₃ etching and an ORMOSIL sol–gel coating was proposed to construct a superhydrophobic functional layer. FeCl₃ etching generated a hierarchical micro/nanostructure on the aluminum surface, while the ORMOSIL layer, formed by the co-hydrolysis and condensation of PFOTES and HDTMS, built Si-O-Si networks and introduced C-F groups to reduce surface energy and enhance stability. The modified surface showed a high water contact angle of 161.44°, confirming excellent superhydrophobicity. AFM analysis revealed a significant increase in surface roughness (Sa = 0.844 μm), confirming the formation of a hierarchical micro/nanostructure. Electrochemical measurements showed a positive shift in corrosion potential from −0.723 V to −0.652 V, demonstrating enhanced corrosion resistance. More importantly, after 120 h of immersion in aviation fuel, the coating maintained a high contact angle of 156.73° and preserved its Si-O-Si network and fluorinated functional groups, confirming outstanding fuel resistance and long-term stability. These results demonstrate that the proposed ORMOSIL coating is a promising protective strategy for aviation fuel systems operating under low-temperature and corrosive conditions. Full article

Heat accumulation during wire-laser directed energy deposition (WL-DED) may cause the thermal softening of thin aluminum alloy substrates. In this study, a liquid nitrogen-assisted cooling platform was introduced to regulate the substrate temperature during WL-DED of a 6061 aluminum alloy substrate with 5356 aluminum alloy wire. The results show that substrate cooling can mitigate substrate softening, and −100 °C provides improved substrate-bottom hardness while maintaining acceptable bonding quality. The hardness variation is discussed in relation to reduced thermal exposure, grain-size variation, recrystallization behavior, and the possible retention of strengthening phases. This work establishes a preliminary basis for tailoring the local properties of thin aluminum alloy substrates in WL-DED. Since the substrate is not removed, but forms an integrated component of the final assembly along with the deposited material, its properties are critical to component performance. This integrated approach also enhances material utilization and streamlines production by eliminating substrate separation steps. Full article

6061 aluminum alloy is lightweight and has good thermal conductivity, while 304 stainless steel possesses excellent mechanical properties and corrosion resistance; both have broad application prospects in cooling circuits. Propylene glycol coolant shows great potential in liquid cooling systems due to its low toxicity and good antifreeze properties. However, during operation, galvanic corrosion may occur when the two metals come into direct contact within the coolant, thereby threatening system safety and service life. This study focuses on 6061 aluminum alloy, 304 stainless steel, and their galvanic couples. Electrochemical testing, SEM, 3D confocal microscopy, and XPS were used to systematically investigate their self-corrosion and galvanic corrosion behavior in propylene glycol coolant at pH values of 4.8, 6.8, and 8.8. The results indicate that 6061 aluminum alloy is more sensitive to pH changes; its corrosion resistance first increases and then decreases as pH rises, with the least corrosion occurring at pH = 6.8 and the most severe at pH = 4.8. 304 stainless steel exhibited lower corrosion rates at pH 6.8 and 8.8, but corrosion significantly worsened at pH 4.8. For the 6061 aluminum alloy/304 stainless steel couple, the galvanic current first decreased and then increased with rising pH, while the galvanic potential first increased and then decreased. The 6061 aluminum alloy consistently acted as the anode, and the 304 stainless steel consistently acted as the cathode, with the highest sensitivity to galvanic corrosion observed at pH 4.8. XPS analysis shows that under different pH conditions, the corrosion products of 6061 aluminum alloy are Al(OH)₃ and Al₂O₃, while the main components of the passivation film on 304 stainless steel remain unchanged. Full article

Aluminum alloys are attractive for oil production, refining, and hydrocarbon-processing equipment because of their low density, high specific strength, and heat-transfer properties; however, their use is limited by localized corrosion in chloride-, sulfur-, and water-containing environments. This review analyzes combined anodic oxide/polymer and anodic oxide/fluoropolymer coating systems as surface-engineering approaches for improving corrosion resistance, adhesion, and durability of aluminum alloys under such conditions. The reviewed data show that coating performance is governed by anodic oxide morphology, pore sealing or polymer impregnation, and oxide/polymer interfacial stability. Quantitative results indicate that anodizing and pore widening can increase aluminum/polyamide lap-shear strength from 5.0 to 17.4 MPa, while optimized interfacial treatment can provide 22.5 ± 0.5 MPa before aging and 18.1 ± 0.2 MPa after humid aging. Corrosion data show that anodizing can increase the polarization resistance of aluminum alloy 6061 in seawater from 17.2 kΩ·cm² to 2.24 MΩ·cm². For wear-related durability, optimized anodizing can increase the critical scratch load from 37.3 to 118.9 N. These values provide practical benchmarks for designing anodic oxide/polymer systems for complex oilfield and hydrocarbon-processing environments. Full article

Understanding the respective roles of thermal and athermal effects during electric current treatment is critical for advancing current-assisted processing of metallic materials. In this study, strain hardening in cold-rolled A6061 was effectively relieved using high-density pulsed electric current. By conducting comparative experiments under room-temperature and liquid-nitrogen conditions, the thermal and athermal contributions were quantitatively evaluated. The results indicate that thermal effects dominate over athermal effects in dislocation density reduction and strain-hardening relief. Nevertheless, the athermal effect, driven by electron wind force, is capable of promoting dislocation motion and annihilation. This work provides a practical framework for evaluating thermal and athermal contributions and offers new insights into microstructure control via electric current, with implications for the design of advanced structural materials. Full article

Dissimilar 7075-T6 and 6061-T6 aluminum alloy joints were fabricated using pulsed metal inert gas (P-MIG) welding with ER5356 filler wire. The effects of welding current (224 A, 234 A, and 244 A) on macro-morphology, microstructure, mechanical properties, and corrosion behavior were systematically investigated. As welding current increased, the top and bottom reinforcements first increased and then decreased, reaching maximum values at 234 A, while the front weld width exhibited the opposite trend. The weld zone consisted of equiaxed and dendritic grains, with partial remelting of AlFeMnSi intermetallic compounds observed in the heat-affected zones. The microhardness and tensile strength of the joints followed a similar trend of first decreasing and then increasing with welding current, achieving a maximum tensile strength of 203.9 MPa at 244 A, corresponding to 89.5% of the 6061-T6 base metal strength. Corrosion resistance varied across regions depending on the evaluation method. In intergranular corrosion tests, the 7075-HAZ showed the highest susceptibility due to grain boundary segregation of Mg and Zn. In electrochemical tests, the WZ exhibited the poorest corrosion resistance. For the 7075-HAZ, optimal corrosion resistance was achieved at 234 A, attributed to a stable passive film and uniform precipitate distribution. These findings provide valuable guidance for optimizing P-MIG welding parameters for dissimilar 7075/6061 aluminum alloy joints. Full article

To meet the requirements for passive heat dissipation and self-cleaning of aluminum alloy enclosures used in 5G base-station active antenna units (AAUs), a scalable surface modification strategy involving sandblasting, NaOH etching, and PFTEOS grafting was developed for 6061 aluminum alloy. Microscale rough structures were first constructed by sandblasting, and hierarchical micro/nano structures composed of microscale pits and nanoscale plate-like/coral-like features were subsequently formed through NaOH etching and boiling-water treatment. Finally, a low-surface-energy PFTEOS layer was grafted onto the structured surface to achieve superhydrophobicity. The effects of sandblasting pressure and etching time on surface morphology, chemical composition, wettability, and infrared emissivity were systematically investigated. The results show that sandblasting enhanced infrared emissivity by increasing surface roughness and promoting optical trapping, while NaOH etching further improved emissivity through the formation of hierarchical micro/nano structures and infrared-active AlOOH/Al₂O₃ phases. After PFTEOS grafting, the surface wettability changed from hydrophilic to superhydrophobic, while the high infrared emissivity was maintained. Compared with the untreated aluminum alloy, the modified surface exhibited a remarkable increase in water contact angle from 80.10° to 153.63° and infrared emissivity from 0.0102 to 0.8951. Moreover, the water contact angle remained above 150° after continuous water-jet impact, indicating good preliminary resistance to hydraulic shear. This work provides a feasible surface-engineering route for integrating high infrared emissivity and self-cleaning capability on aluminum alloy surfaces for outdoor thermal management applications. Full article

Aiming at the urgent heat dissipation demands of high-power, high-integration electronic devices, Cu/Al composite heat sinks combine the high thermal conductivity of copper and the lightweight advantage of aluminum, becoming a mainstream solution for advanced thermal management systems. The significant physicochemical differences between Cu and Al, however, make high-quality joining a technical bottleneck. In this study, flux-free ultrasonic brazing with a Zn-based filler metal was used to join 6061 aluminum alloy and industrial pure copper. Gradient heat treatment (55–300 °C) was subsequently applied to systematically investigate its effect on the microstructure, microhardness, and thermal properties of the joints. The results show that the as-brazed joint exhibited excellent bonding (97.3% bonding rate) and shear strength (95.24 MPa). The weld seam consisted of Zn solid solution, Cu solid solution, and Al-Cu-Zn ternary compounds. Heat treatment did not induce new phases but led to the coarsening of Zn-Al-Cu compounds and aggregation of the eutectic structure, reducing grain boundaries. Consequently, the microhardness at the weld center varied non-monotonically, and the thermal conductivity of the joint showed an overall increasing trend with rising heat treatment temperature. This enhancement is attributed to reduced phonon scattering at diminished grain boundaries. This study clarifies the heat treatment–microstructure–thermal properties relationship, providing important guidance for the thermal performance optimization of Cu/Al composite heat sinks. Full article

Surface protection and functional modification of aircraft-certified aluminum alloys are essential for corrosion resistance, durability, and long-term airworthiness. At the same time, increasingly restrictive environmental regulations motivate the development of alternatives to legacy wet-chemical surface treatments. This study presents an integrated assessment of ultrafast femtosecond laser surface texturing as a surface functionalization approach for Aluminum 6061 alloys within an aerospace manufacturing and sustainability context. Ultrashort-pulse laser processing enables controlled micro- and nano-scale surface topographical modification with limited thermal impact, allowing adjustment of wettability and surface functionality while preserving bulk material integrity. As a dry and contactless process, femtosecond laser treatment eliminates the use of hazardous chemicals, reduces consumable inputs, and generates minimal secondary waste. A streamlined cradle-to-gate life cycle assessment conducted in accordance with ISO 14040/14044 indicates a lower global-warming potential per functional unit compared with conventional surface treatments, including anodization, plasma-assisted coatings, and organic coating systems. Complementary qualitative analyses addressing environmental health and safety, supply-chain risk, and ESG alignment indicate potential advantages related to occupational safety, regulatory compliance, waste management, and end-of-life recyclability. The investigation is performed on planar Aluminum 6061 reference surfaces with a treated area of 25 mm², providing a controlled laboratory-scale basis for analyzing process behavior, functional surface modification, and associated environmental metrics. Within this defined scope, the results support further evaluation of femtosecond laser surface texturing as a surface engineering option for future aerospace manufacturing. Full article

Accurate prediction of cutting force is essential for process optimization and intelligent control in CNC turning, yet cross-material performance comparisons of machine learning models remain limited. This study develops and applies a structured diagnostic benchmarking framework to evaluate ten supervised regression models for cutting force prediction across five engineering alloys: Aluminum Alloy 6061, Brass C26000, Bronze C51000, Stainless Steel 304 (annealed), and Carbon Steel 1020 (annealed). The input space included material category together with machining descriptors (diameter, feed rate, and axial distance from the chuck). Model performance was evaluated using the coefficient of determination (R²), root mean square error (RMSE), cross-validated stability metrics, and pairwise dominance probability matrices derived from R² and CV(RMSE). Gradient Boosting achieved the highest overall accuracy and robustness, with a mean R² = 0.962 and RMSE = 18.03 N, followed by a feedforward neural network (R² = 0.953, RMSE = 19.96 N), while Support Vector Regression showed substantially lower performance (R² < 0.65; RMSE > 54 N). Residual diagnostics indicated that ensemble and neural models produced compact, near-homoscedastic error distributions, whereas linear and single-tree models exhibited systematic bias and heteroscedasticity. Principal Component Analysis revealed that the first two components captured 78.7% of the total variance, separating geometric and spatial effects from feed-driven variability. The proposed evaluation framework provides a unified methodology for accuracy, and multivariate interpretation in machining force prediction. These results offer practical guidance for selecting robust learning models in intelligent CNC systems and data-driven manufacturing environments. Full article