最新刊期
卷 44 ， 期 11 ， 2024
- “在铸造工艺领域，专家提出了基于BP神经网络与改进粒子群算法的夹杂预测与工艺优化方法，精度提升至94.7%，缺陷率降低52%和40%。”摘要：A method of inclusion prediction and process optimization was proposed based on BP neural network and improved particle swarm optimization algorithm. Firstly， data mining and cleaning were conducted based on Huazhu ERP. Secondly， a defect prediction model （Particle Swarm Optimization-Back Propagation， PSO-BP） combining particle swarm optimization algorithm and BP neural network was established，of which the accuracy is improved from 92.1% to 94.7% compared with ordinary BP neural network. Finally， a process optimization method （K-Nearest Neighbors Imputation-Improved Particle Swarm Optimization， KNN-IPSO） was proposed. The simulation results indicate that the defect rate is reduced by 52% and 40% compared with that under different disturbances.关键词：Investment Casting;BP Neural Network;Improved Particle Swarm Optimization Algorithm;K-nearest Neighbor Interpolation Method
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发布时间：2024-12-02 - “在增材制造领域，研究者利用激光熔化沉积技术，通过双层Cu合金中间层实现钛合金与钢的高质量连接，避免了金属间化合物生成和裂纹缺陷。”摘要：The laser melting deposition technique was applied to connect TC4 titanium alloy with medium carbon low alloy steel as substrate and single- and double-layer copper alloy as interlayer. The microstructural evolutions of steel/titanium dissimilar interfaces were investigated. The results indicate that the formation of Ti-Fe intermetallic compounds is always observed taking the single layer of pure copper as interlayer， resulting in cracking of interface and titanium alloy layer. With the double layer of copper alloy as interlayer， the inter-diffusions of Ti and Fe elements are effectively hindered， leading to a well-bonded steel/titanium joint without obvious pores or cracks. Significant microstructural differences are observed between interlayers， where the first layer shows a fine equiaxed grain structure， due to the heterogenous nucleation effects of Fe-rich particles， and the second layer shows a slightly coarser columnar grain structure， as the result of the directional heat flux.关键词：Additive Manufacturing;Steel/Titanium Joint;Dissimilar Materials;Bonding Interfaces;Microstructure
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发布时间：2024-12-02 - “在增材制造领域，机器学习技术识别数据模式，优化工艺参数，提升零件性能，为过程控制与性能优化提供指导。”摘要：Additive manufacturing is widely used in medicine and aerospace fields. However， it still faces challenges such as limited material types， unstable part quality and mechanical properties， and the complex relationship between process parameters and mechanical properties. As a key technology in artificial intelligence， machine learning has the advantage of recognizing patterns and trends in data， promoting research in additive manufacturing. The application of machine learning in additive manufacturing was reviewed， including the selection of model parameters， prediction of metallurgical defects and performance， in-situ monitoring， and optimization of alloy composition， process， and geometric structure， aiming to provide guidance for process control and performance optimization in additive manufacturing.关键词：Machine Learning;Additive Manufacturing;Real-time Monitoring;Defect Control;Mechanical Properties
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发布时间：2024-12-02 - “精密铸造技术新突破，ZL205合金成形能力提升，500°C预热、空冷条件下极限成形能力约3毫米。”摘要：Based on investment casting technology， the inverse calculation of heat transfer coefficient of pouring interface in ZL205 alloy was realized through multi-point temperature measurement and finite element （FE） calculation to improve the accuracy and reliability of physical field solution. On this basis， the FE simulation and experimental verification of pouring process were carried out on multi-type and multi-size parts under the preheating condition of 200， 500 ℃ as well as natural and air-cooling. The flow， solidification， ultimate castability and defect prevention of the alloy were discussed. It is found that the preheating of high shell can significantly improve the forming ability of alloy and inhibit casting defects. The ultimate forming ability of ZL205 alloy is about 3 mm under the preheating condition at 500 ℃ and air cooling.关键词：ZL205 Alloy;Investment Casting;Interfacial Heat-transfer Coefficient;Finite Element Calculation
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发布时间：2024-12-02 - “在砂型铸造领域，专家基于大数据模型分析，有效减少铸件缺陷，提高生产效率。”摘要：Aiming at complex sand-casting process combined with the interactions between process parameters and difficulty in controling casting quality as well as high scrap rate， a data-driven model was proposed to reduce casting defects and improve production efficiency. The collected data were utilized for data preprocessing， including four types of defects and corresponding process parameters. The high-dimensional data was reduced to 3D， and the distribution， clustering， trend and other information were visually displayed through 3D scatter diagram. The random forest （RF） classification model was established， and the results indicate that the recall rates of all categories reach above 90%. The influence degree of different process parameters on defects was obtained by Gini impurity analysis of the model. Finally， Monte Carlo （MC） simulation method was employed to predict the optimal distribution of process parameters.关键词：Sand Casting Process;Data-driven;Classification Model;Quality Prediction;Feature Importance
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发布时间：2024-12-02 - “在电弧增材制造钛合金领域，专家总结了原位合金化方法，分析了合金化元素对组织和性能的影响，为提升钛合金性能提供新思路。”摘要：The intrinsic high cooling rate and temperature gradient during wire and arc additive manufacturing （WAAM） process can result in coarse primary β columnar grains in deposited titanium alloys， which deteriorates the plasticity and fatigue properties. In-situ alloying was employed to introduce the element with high growth limiting factor in order to alter solidification of molten pool and promote the equiaxed transformation of columnar grains， which is an effective method to improve the properties of deposited Ti alloys. The in-situ alloying methods in WAAM process were summarized， and influence of nonmetallic and metal-alloyed elements on microstructure and mechanical properties of WAAM Ti alloys， as well as the transformation mechanism of columnar grains were investigated. The composition design of titanium alloys for WAAM was prospected.关键词：Alloying;Additive Manufacturing;Titanium Alloy;Microstructure
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发布时间：2024-12-02 - “在工业4.0时代背景下，元宇宙和AR技术在工业应用中展现出巨大潜力。研究了元宇宙和AR技术在高压铸造岛全生命周期中的应用，提高了协同设计效率，并在运维阶段提供实时直观支持。展望了其在提高装备工业设计和运维效率方面的潜力。”摘要：With the advent of the Industry 4.0 era， the potential of metaverse and augmented reality （AR） technology in industrial applications is increasingly evident. In recent years， the urgent demand for integrated die-casting of large structural components has promoted the rapid development of the die-casting equipment industry towards large-scale， intelligent， and digital directions. The high-pressure die-casting island was analyzed emphatically， and the application of metaverse and AR technology in the whole lifecycle was discussed. Results indicate that the collaborative design efficiency of high-pressure die casting island is improved by utilizing the virtual simulation capability of the metaverse and the intuitive interaction characteristics of AR. Meanwhile， real-time and intuitive guidance can be provided during the operation and maintenance period of the high-pressure die casting island. Finally， the future application prospects of metaverse and AR technology in the industrial field were addressed， and the broad potential in improving equipment industrial design and operation efficiency was prospected.关键词：High-pressure Die Casting Island;Metaverse Technology;Augmented Reality;Industry 4.0
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发布时间：2024-12-02 - “在压铸铝合金领域，专家利用LASSO回归和机器学习技术，建立了力学性能预测模型，为材料性能优化提供新方案。”摘要：Based on the data of “composition-as-cast mechanical properties” of die-cast aluminum alloy obtained in literature and experiments， influence rules and degrees of different elements on yield strength， tensile strength and elongation were obtained by LASSO regression. The linear prediction model within the small fluctuation range of components was obtained. Nonlinear machine learning methods， including BP neural network， random forest， Adaboost and support vector machine were used to fit the entire dataset. The results indicate that the BP neural network has the desirable prediction ability of yield strength and elongation， and the random forest model has the optimal prediction ability of tensile strength after hyperparameters optimization.关键词：Machine Learning;High Pressure Die Casting;Aluminum Alloy;Prediction of Mechanical Properties;Heat-free Treatment
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发布时间：2024-12-02 - “在激光选区熔化成形AlSi10Mg合金领域，研究了不同扫描路径和预热温度对残余应力的影响。结果表明，预热温度对残余应力的影响更为显著，随着基板预热温度的升高，残余应力最高降低了42.7%。”摘要：The finite element method was used to simulate the variation tendency of residual stress of AlSi10Mg processed by selective laser melting based on different scanning paths and preheating temperature. The results indicate that compared with the scanning path， preheating temperature has a more significant effect on the residual stress of AlSi10Mg. With the preheating temperature of the substrate increased from 80 ℃ to 300 ℃， the temperature field distribution becomes more uniform and the maximum residual stress is decreased by 42.7%. Compared with the long-path scanning mode， the short-path scanning mode has a smaller average temperature gradient and temperature standard deviation with a lower residual stress.关键词：Selective Laser Melting;AlSi10Mg;Scanning Path;Preheating Temperature;Residual Stress
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发布时间：2024-12-02 - “在铝合金发动机缸体制造领域，专家基于田口设计和灰色关联分析，优化了工艺参数，显著提升了铸件质量和生产效率。”摘要：Taking ZL114A aluminum alloy engine block as object， process parameters including pouring temperature， charging and pressurizing speed， holding pressure and holding time as influencing factors based on the initial process， and porosity and solidification time as molding quality evaluation targets， 16 groups of orthogonal tests were designed based on Taguchi's design method， and the multi-objective correlation analysis was carried out based on gray correlation analysis method. The results indicate that the optimized combination of process parameters is determined as pouring temperature of 700 °C， filling and pressurizing speed of 1.2 kPa/s， holding pressure of 65 kPa and holding time of 220 s， where the porosity and solidification time are reduced by 18.5% and 3.7%， respectively， compared to those of ones in the initial process. After production verification， the casting molding quality is desirable with excellent mechanical properties， verifying the feasibility of optimized process parameters， which is conducive to the improvement of production efficiency and product qualification rate.关键词：Process Parameters;Aluminum Alloy;Grey Correlation Analysis;Cylinder Block
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发布时间：2024-12-02
Topic·Intelligent Casting and Additive Technology
- “最新研究发现，采用瓷刚铝合金TiB2/Al制备的导电铝材，在提高弹性模量的同时，实现了强塑性和电导率的优异组合。”摘要：The ceramic-rigid TiB2/Al was applied to fabricate aluminum conductor to obtain superior combination of strength， ductility and electrical conductivity on the basis of greatly improving the elastic modulus. TiB2 particles were in-situ generated in the molten aluminum through halide salt reactions to reinforce aluminum matrix. Compared with pure alloys， the grain size of ceramic-rigid TiB2/Al is significantly refined. With 2% TiB2 addition， the tensile strength， yield strength， elongation， conductivity and elastic modulus of 1070 aluminum alloy reach 161.7 MPa， 150.6 MPa， 7.76%， 35.786 MS/m， and 73.1 GPa， respectively. After 0.5% TiB2 addition， the tensile strength and conductivity of 6201 aluminum alloy are increased by 55 MPa and 1.606 6 MS/m， while the elongation is hardly reduced.关键词：TiB2 Particles;Ceramic-rigid TiB2/Al;Electrical Conductivity;Mechanical Properties
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发布时间：2024-12-02
Research·Composites
- “据最新研究，抗菌不锈钢材料在力学、抗菌、耐腐蚀性能方面取得进展，为新型抗菌金属材料开发提供参考。”摘要：The mechanical， antibacterial， corrosion resistance， and action mechanism of commonly used antibacterial stainless steel materials were reviewed， and the advantages and disadvantages of different types were pointed out. Copper ion type and silver ion type antibacterial stainless steels have the disadvantages of solid solution and active chemical properties， respectively. The antibacterial stainless steel containing copper and silver elements can greatly improve the antibacterial rate， and the mechanical and corrosion resistance properties are hardly reduced. Gallium containing antibacterial stainless steel has excellent and unique disease resistance toxicity. Cerium has a synergistic effect with other antibacterial substances， which has good development prospects， providing a reference for the development of new antibacterial metal materials. The characteristics of antibacterial stainless steel containing different elements were discussed， and the future research directions were described.关键词：Alloying Type;Antibacterial Stainless Steel;Gallium;Copper Silver
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发布时间：2024-12-02
Research·Review
- “在消失模铸造高锰钢衬板领域，通过ProCAST软件模拟，发现侧注式浇注的C工艺效果最佳，有效减少缩孔缩松缺陷。”摘要：For the problems of high tendency of shrinkage holes and shrinkage porosities in high manganese steel liner by lost foam casting， ProCAST software was used to simulate the liner filling and solidification process of process A with top injection casting of 8 pieces in a box， process B with step side injection casting of 10 pieces in a box and process C with side injection casting of 4 pieces in a box， and the casting defects were evaluated. The results indicate that the filling process of metal liquid with process A presents flow disturbance， while that of process B is more turbulent and that of process C is relatively smooth. Specially， the defects in the middle 6 liner plates of process B are more scattered and located close to the surface of the liner plates， while the defects in the liner plates of process C are concentrated in the core. The optimized LFC process is the process C with side injection casting.关键词：Ball Mill Liner;Shrinkage;ProCAST;Lost Foam Casting
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发布时间：2024-12-02 - “在高温变形条件下，Ti-6.5Al-3.5Mo-1.5Zr-0.3Si合金的微观组织演变及球化机理被深入研究，为合金加工提供理论依据。”摘要：The compression tests were carried out for Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy in the temperature range of 750~950 ℃ and strain rate range of 0.001~10 s-1 at 50% reduction by thermal simulator. The flow stress curves were analyzed， and the strain-compensated constitutive equation with high accuracy were established based on Arrhenius type hyperbolic sine equation， where the strain is implied in the material constants. Effects of strain rate and deformation temperature on microstructure were investigated using metallographic microscope， and the spheroidization mechanism was analyzed using TEM. The results indicate that α lamella is dominated by bending and elongation with the strain rate higher than 0.01 s-1 under all deformation temperatures， and the spheroidization is inconspicuous. With the strain rate decreasing to 0.01 s-1， α lamella starts to spheroidize， and the spheroidization fraction is increased with the decrease of strain rate and increase of deformation temperature. In addition， the size of α phase is increased with increasing deformation temperature， and the transition of α→β phase occurs simultaneously. The spheroidization mechanisms are characterized by boundary splitting， shear and dynamic recrystallization.关键词：Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy;Constitutive Equation;Microstructure Evolution;Spheroidization Mechanism
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发布时间：2024-12-02 - “在高温合金领域，专家研究了固溶温度和冷变形对Haynes 230合金晶粒长大的影响，建立了晶粒长大模型，为合金性能优化提供依据。”摘要：Effects of solution temperature and cold deformation on austenite grain growth of Haynes 230 superalloy were investigated. The cold-rolled plates of Haynes 230 superalloy with different solution temperatures and deformation amounts were solution treated for 15 min， and the average austenite grain size after solution treatment was measured. A model for austenite grain growth of Haynes 230 alloy under different deformation amounts was established by Arrhenius formula. The results indicate that the austenite grain size is decreased with the increasing of deformation rate at given temperature. At given deformation rate， the austenite grain size is increased with the increasing of solution temperature， presenting characteristics of firstly slow and then acute. The activation energies of austenite grain growth under different deformation amounts are 47， 52 and 119 kJ/mol.关键词：Nickel-based Superalloy;Solution Treatment;Cold Deformation;Grain Size;Microstructure
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发布时间：2024-12-02 - “在铝合金领域，研究者发现超声振动功率显著影响ZL114A-0.6Y合金的微观组织和力学性能，1200W超声处理后合金性能最佳。”摘要：In view of the insufficient mechanical properties of ZL114A-0.6Y alloy， influence of continuous ultrasonic vibration power on microstructure and mechanical properties of ZL114A-0.6Y alloy was investigated， and the mechanism was described. The results indicate that ultrasonic vibration power has a significant effect on the microstructure of ZL114A-0.6Y alloy. With the increase of ultrasonic power， the size of α-Al dendrite is decreased firstly and then increased， and the morphology is converted from dendritic and petal shape to granular and fine equiaxial shape. At 1 200 W， the microstructure is desirable with the desirable grain size， and the eutectic silicon morphology presents short rod shape with uniform distribution. In addition， the volume of Y phase is decreased， and most of Al3Y compounds exist at the grain boundary of Al-Si phase in form of punctiform and blocky. Ultrasonic vibration power has a significant effect on mechanical properties of alloy，reaching optimal at 1 200 W， where the average microhardness， tensile strength and elongation reach 124.26 HV， 314 MPa and 5.3%， respectively.关键词：ZL114A-0.6Y Alloy;Ultrasonic Power;Microstructure;Mechanical Properties
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发布时间：2024-12-02 -
Effects of Solution Temperature on Microstructure and Mechanical Properties of TC21 Titanium Alloy AI导读
“报道：TC21钛合金固溶温度对其微观组织和力学性能有显著影响，固溶温度升高导致初生α相减少，强度先升后降，塑性持续降低。”摘要：Taking TC21 titanium alloy as object， the temperatures of two-phase region and single-phase region were set for solid solution treatment according to the phase transition point. Effects of solid solution temperature on microstructure and mechanical properties of TC21 titanium alloy were investigated by means of microstructure observation， phase analysis， tensile property and fracture analysis. The results indicate that the solution temperature has a great influence on the microstructure of alloy. During the increasing process of solution temperature， the quantities of primary α phase in the microstructure are gradually decreased， and finally disappears completely. The morphology is transformed from long strip to short rod， and the degree of equiaxiallization is gradually enhanced. The strength of alloy presents a trend of rising firstly and then decreasing with the increase of solution temperature， while the plasticity is decreased continuously. Within two-phase region of temperature， the tensile fracture morphology is dominated by dimples， and the fracture type is characterized by ductile fracture. Within single-phase region of temperature， the tensile fracture morphology is dominated by rock-like shape with a small number of small-sized dimples， and the fracture type is characterized by brittle fracture.关键词：TC21 Titanium Alloy;Microstructure;Tensile Properties;Fracture Morphology- 16
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发布时间：2024-12-02
Research·Alloy Process
- “在非晶合金领域，研究人员采用铜模吸铸法制备了Zr50Cu34Al8Ag8合金棒材，分析了其结晶动力学行为，为非晶合金研究提供新方向。”摘要：Zr50Cu34Al8Ag8 amorphous alloy rods were prepared by copper mold suction casting， and the isothermal crystallization kinetics of the alloy was analyzed by differential scanning calorimetry. The results reveal that the increase in isothermal annealing temperature accelerates crystallization process of amorphous alloy. Under isothermal annealing conditions， an average activation energy of 295.4 kJ/mol is calculated for the nucleation growth process of amorphous alloy by Arrhenius equation. During the process， the Avrami index n of Zr50Cu34Al8Ag8 amorphous alloy is in range of 2.0 and 2.5， indicating the the grain growth during the crystallization process accompanied with a decrease in the nucleation rate.关键词：Amorphous Alloy;Isothermal Annealing;Thermal Analysis;Microstructure
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发布时间：2024-12-02 - “在材料科学领域，研究人员利用Al-Ni纳米多层膜制备Al2O3陶瓷/Ni自蔓延焊点，发现焊点剪切强度随Sn层厚度变化，为焊接技术提供新思路。”摘要：Taking Al-Ni nano-multilayer film as the heat source of self-propagating exothermic reaction， Al2O3/Ni self-propagating solder joints were successfully prepared at room temperature. The microstructure， element distribution and phase composition of the cross-section and fracture surface of solder joints were characterized by scanning electron microscopy （SEM）， X-ray energy dispersive spectrometer （EDS） and X-ray diffractometer （XRD）. Effects of Sn layer thickness on microstructure and mechanical properties of solder joints were systematically investigated. The results indicate that the shear strength of solder joints is firstly increased and then decreased with the increase of Sn layer thickness， which reaches the desirable shear strength at 30～40 μm. The solder joints are characterized by brittle fracture， which is mainly formed at the interface of ceramics and nickel coating.关键词：Alumina Ceramics;Al-Ni Nanofoil;Self-propagating Combustion Reaction;Low-temperature Joining
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发布时间：2024-12-02 - “在高温合金制备领域，研究了抽拉速率对DZ406合金组织及偏析的影响，为合金制备提供新思路。”摘要：DZ406 nickel-based superalloy specimens were prepared by high rapid solidification （HRS）， and effects of different drawing rates （3， 6， 9 mm/min） on microstructure and segregation of the alloy were investigated. The results indicate that with the increase of drawing rate， the primary dendrite space is decreased from 580.47 μm to 510.29 μm， and the secondary dendrite space is decreased from 69.15 μm to 65.92 μm. The morphology of γ′ phase is transformed from irregular butterfly shape to tightly arranged cubic shape， with the dimension decreased from 0.55 μm to 0.28 μm in interdendritic and 0.27 μm to 0.17 μm in dendritic stem， and the segregation degree is decreased. Moreover， carbide and γ/γ′ eutectic is mainly distributed among dendrites， where the morphology of carbide is converted from block to rod， long strip， particle and network shell， while that of γ/γ′ eutectic phase is transformed from oatmeal to block with decreasing content.关键词：Directional Solidification;Drawing Rates;DZ406 Superalloy;Microstructure;Element Segregation
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发布时间：2024-12-02 -
High-temperature Mechanical Behavior of NbC Precipitation Strengthened NiCoFeCrMn High Entropy Alloy AI导读
“在材料科学领域，研究人员设计了一种NbC沉淀相强化的NiCoFeCrMn高熵合金，该合金在873 K下保持了425 MPa的屈服强度以及50.5%的伸长率，屈服强度提高了77%，伸长率几乎没有损失。”摘要：A NbC precipitation strengthened NiCoFeCrMn HEA was designed. After cold rolling and recrystallization， as-annealed （NiCoFeCrMn）98.4Nb0.8C0.8 HEA exhibits uniform equiaxed grain structure， and a dispersed near-spherical NbC phase was formed. The alloy maintains a yield strength of 425 MPa and a fracture elongation of 50.5% at 873 K. Compared with the matrix alloy， the yield strength is increased by 77%， and the elongation is almost unchanged. In addition， the HEA exhibits serrated flow characteristics at 673～1 073 K， which is mainly attributed to the large lattice distortion of alloy caused by doping of Nb and C elements and precipitation of NbC particles.关键词：High-entropy Alloy;Microstructure;Precipitation Strengthening;Serrated flow- 16
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发布时间：2024-12-02
Research·Alloy Performance
- “在异型差压铸造壳体研究中，发现偏析、缩松等缺陷，严重影响材料力学性能。专家分析了缺陷产生原因，并提出有效预防措施。”摘要：Partial segregation and shrinkage defects appear in local areas of a large counter-pressure ZL205A alloy shell with abnormity figure during X-ray casting inspection. The casting defects were analyzed， and the parts where defects are observed were recorded and the influence on mechanical properties of the castings was analyzed. The origination analysis for defect parts were conducted by sampling observation， metallographic structure， scanning electron microscopy observation （SEM）， energy spectrum analysis and other detection methods. The statistical results reveal that the casting defects are mainly concentrated in the vicinity of the slot ingate， and alloy elements are enriched with different degree in the shrinkage and segregation defect parts， and the defect formation is seriously harmful to the mechanical properties of production. Meanwhile， the fracture observation results reveal that there exist more dimples and river pattern in normal specimens，which are characterized by mixed fracture of toughness and quasi-cleavage fracture， while obvious cleavage steps and intergranular fracture are observed on loose and segregation specimens. Combined with the process analysis， the defects are mainly caused by shrinkage stress of casting， high temperature field and insufficient refining. The mechanism of casting defects formation was discussed， and effective preventive measures were provided including reducing thermal stress， avoiding microstructure overheating and promoting uniform dispersion of alloy components.关键词：ZL205A Alloy;Counter-pressure Casting;Shrinkage;Segregation;Formation Mechanism
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发布时间：2024-12-02
Application·Die Casting
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
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