最新刊期
卷 45 ， 期 2 ， 2025
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Effects of Trace Variation of Al Content on Microstructure and Properties of HPDC Mg-4Sm-2Al Alloy AI导读
“在镁合金领域，研究者分析了微量铝含量变化对SA42合金力学性能的影响，发现添加0.6%铝后，合金屈服强度和伸长率分别降低了10.2%和63.5%。”摘要：SA42 and Mg-4Sm-2.6Al （SA42.6） alloys were fabricated by HPDC process， and influence of trace Al content on mechanical properties was systematically analyzed. The results indicate that with 0.6% Al addition to SA42 alloy， the yield strength and elongation are reduced by 10.2% and 63.5%， respectively， which is attributed to the large quantities of massive Al2Sm phases generated by reaction between Al and Sm dissolved into the matrix， leading to an approximate 50% reduction in Sm concentration within Mg matrix， significantly diminishing solute strengthening effects. The contributions from secondary phase strengthening as well as grain boundary strengthening provided by formed Al2Sm can hardly compensate for the loss in solid solution strengthening effect， resulting in an approximate reduction of 20 MPa in yield strength for SA42.6 compared to that of SA42. The substantial decrease in elongation primarily arises from modulus mismatch between Al2Sm particles and Mg matrix. The brittle and hard Al2Sm particles induce great stress concentrations during deformation processes， thereby accelerating fracture and failure.关键词：Mg Alloy;Mechanical Properties;Die Casting;Microsturcture526|63|0更新时间：2025-02-24 -
Electrochemical Properties of Martensitic Stainless Steels in Simulating Biological Environments AI导读
“最新研究发现，440C、BD1N、S35VN马氏体不锈钢在人工唾液和硼酸盐缓冲液中表现出良好耐蚀性，其中440C性能最佳。”摘要：The electrochemical properties of 440C， BD1N and S35VN martensitic stainless steels in artificial saliva （AS） and borate buffered saline （BBS） were investigated by potentiodynamic polarization tests， electrochemical impedance spectroscopy （EIS）， optical microscopy （OM）， scanning electron microscopy （SEM）， energy dispersive X-ray spectroscopy （EDS） and X-ray photoelectron spectroscopy （XPS）. Potentiodynamic polarization curves reveal that passivation occurrs for all the samples， indicating desirable corrosion resistance. The circular arc shape of EIS results illustrates that the electrode processes are controlled by the electrochemical reactions. The 440C sample exhibits small corrosion current density Jcorr， high corrosion potential Ecorr， large arc radius， large sum of charge transfer resistance and passivation film resistance Rct+Rf， indicating optimal corrosion resistance. The corrosion resistance is presented as follows： 440C > BD1N > S35VN. The corrosion products are mainly composed of FeO， Fe2O3， and Cr2O3.关键词：Martensitic Stainless Steel;Corrosion;Electrochemical Properties;Simulating Biological Environments74|45|0更新时间：2025-02-24
Current Recommendation
- “镁合金室温超塑性变形研究取得新进展，专家提出晶界滑移机制，为材料应用提供新思路。”摘要：Grain boundary slip mechanism during magnesium alloy superplasticity deformation was described， and the necessity of introducing grain boundary slip deformation mechanism to achieve superplasticity at room temperature was put forward. On this basis， based on the constitutive equation of superplastic deformation controlled by grain boundary slip， the way of introducing grain boundary slip into superplastic deformation of magnesium alloy at room temperature was reviewed. Finally， the research status of superplastic deformation of magnesium alloys at room temperature was summarized， and the research direction was prospected.关键词：Mg Alloy;Room-temperature Superplasticity;Grain Boundary Segregation;Grain Boundary Sliding72|50|0更新时间：2025-02-24
- “陶瓷型芯制备技术取得新进展，为高性能陶瓷型芯制造提供新思路。”摘要：In view of the exsiting problems such as imprecise dimensional control， substandard strength， fracture and deformation during the preparation of ceramic cores， the classification and characteristics of ceramic cores as well as main preparation methods were introduced. The latest research progress on ceramic cores in recent years was expounded， and mechanism of mineralizer regulating the performance of ceramic cores was emphasized. The future development of ceramic core manufacturing technology and application of high-performance ceramic cores were prospected.关键词：Investment Casting;Ceramic Core;Mineralizer;Performance Regulating40|80|0更新时间：2025-02-24
- “在铸件飞边检测领域，基于DETR网络，提出了一种小样本目标检测算法，有效提高了检测精度。”摘要：In view of small amounts of specimens of casting fringe during detection process and the insufficient fusion of model feature， a few-shot target detection algorithm characterzied by attention-weighted feature fusion was proposed based on DETR network to realize the automatic detection of casting fringe. Firstly， a pyramid feature fusion network with coordinate attention weighting was designed to improve interactive fusion capability and interest region focus of model feature information. Then， the relative position coding of 2D image was introduced to enhance the pattern recognition ability for translation invariance. Smooth-L1 optimized loss function was introduced in the post-processing stage to improve detection accuracy. The results indicate that the detection accuracy of modified algorithm is 47.50%， 54.06%， 66.00%， and 79.32% in test case of 3， 5， 10， and 30， respectively， indicating higher detection accuracy of modified algorithm on the homemade casting fretting dataset.关键词：Target Detection;Few-shot;Castings;Feature Weighted Fusion;Relative Position Coding69|203|0更新时间：2025-02-24
- “核电动作部件耐磨耐蚀合金研究取得新进展，为核用材料发展提供新方向。”摘要：The research status on existing wear-resistant and corrosion-resistant alloys for action components of nuclear power were reviewed， including cobalt-based alloy， nickel-based alloy， iron-based alloy and high-entropy alloy. Moreover， the wear resistant mechanism of cobalt-based alloys was summarized. The manufacturing process of action components was described， and future development trend of wear-resistant and corrosion-resistant materials was prospected.关键词：Nuclear Power;Action Components;Wear;Wear-resistant and Corrosion-resistant Alloys49|62|0更新时间：2025-02-24
Research·Review
- “科技媒体新闻记者报道：基于伯努利方程，专家推导了浸入式水口流量计算式，设计水模型试验装置，研究水头高度和塞棒开口度对流量的影响，建立开浇过程控制模型，验证了方法的准确性。”摘要：Based on the Bernoulli equation of fluid mechanics， the flow calculation formula of submerged nozzle was derived， and a water model experimental device was designed based on the similarity theory. Effects of head height of tundish and opening degree of stopper-rod on nozzle flow were investiagted， and the relationship between opening degree and flow coefficient was determined. It is confirmed that the flow coefficient is a function of opening degree， which is increased with the opening degree. On this basis， the actual pouring process data of a plant was analyzed， and the relationship between flow coefficient and opening degree was verified. The control model of start-up was established， and the control curve was given. The accuracy was verified by the on-site pouring experiment.关键词：Continuous Casting;Submerged Nozzle;Stopper-rod;Automatic Start-up;Control Model34|52|0更新时间：2025-02-24
- “在连铸工艺研究领域，专家建立了铸坯凝固组织模型，验证了模型准确性，为提高GCr15轴承钢铸坯质量提供解决方案。”摘要：A solidification structure model was established based on CAFE module in ProCAST to explore the influence of continuous casting process conditions on solidification structure of GCr15 bearing steel billet， and the accuracy was verified in terms of temperature field and solidification structure. Effects of superheat of molten steel， drawing speed of billet and cooling intensity of secondary cooling zone on solidification structure of continuous casting billet were investigated. The results indicate that the proportion of central equiaxed crystals is increased and grains are refined by reducing superheat and secondary cooling intensity as well as enhancing drawing speed， where the effect of superheat reduction is the most obvious. For each 10 ℃ decrease， the average proportion of central equiaxed crystals is increased by 15.80% and the average grain size is decreased by 3.18%. With enhancing the drawing speed or decreasing the secondary cooling strength， the proportion of equiaxed grains and the number of grains in the center of casting billet are also increased， which have a less effect than that of changing superheat.关键词：Bearing Steel;Billet Continuous Casting;Solidification Structure;Numerical Simulation26|22|0更新时间：2025-02-24
- “报道：研究团队针对6061-T6铝合金管材，通过NSGA-Ⅱ算法优化变截面轴管设计，实现轻量化与性能提升。”摘要：In order to obtain a variable section aluminum alloy driveshaft tube with light weight and excellent dynamic characteristics， the variable section structure with prior critical speed was determined by comparing different variable section shaft tube structures with 6061-T6 aluminum alloy tube as object. With the minimum mass and maximization of the first-order natural frequency of selected variable section shaft tube after high pressure forming as optimization objective， blank wall thickness as structural variable， forming internal pressure and axial feed amount as process parameter variables， and the minimum wall thickness after forming as forming quality constraint， the Pareto solution set of the mass and first-order natural frequency of variable section shaft tube was acquired to obtain optimal solution based on finite element technology， response surface test and NSGA-Ⅱ multi-objective optimization algorithm， and the feasibility was verified by simulation.关键词：Aluminum Alloy Driveshaft Tube;Internal High Pressure Forming;Response Surface Test;Multi-objective Optimization;Pareto Solution Set28|35|0更新时间：2025-02-24
Research·Computer Application
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Manufacturing of Thin-walled Impeller Based on Optimization of Sand Mold 3D Printing Forming Process AI导读
“在3D打印成形工艺领域，专家通过优化试验，确定了最优工艺参数组合，成功试制出满足技术要求的薄壁叶轮铸件。”摘要：The Box-Behnken response surface method was used to optimize the sand mold 3D printing forming process. The horizontal range of resin inkjet content， activator content and printing layer thickness was determined taking tensile strength and gas evolution as response. The optimal combination of process parameters was carried out using numerical simulation， and the thin-walled impeller was trial-produced by low pressure die casting process for verification. The results indicate that when the content of resin inkjet is 1.44%， the content of activator is 0.21%， and the printing layer thickness is 0.30 mm， the tensile strength and gas evolution of printed sand mold reach 2.15 MPa and 8.92 mL/g， respectively， which is close to the predicted value. Under the optimized process conditions， the profile of impeller casting is complete and clear， meating the technical requirements.关键词：3D Printing Sand Mold;Forming Process;Response Surface Method;Low Pressure Die Casting61|78|0更新时间：2025-02-24 - “在钛合金砂型铸造领域，专家研究了磷酸盐粉末对SLS双组分覆膜熔融陶瓷砂型强度的影响，为提高钛合金铸件质量提供新方案。”摘要：Taking coated fused ceramic sand as raw material， influence of phosphate powder addition on the initial strength， curing strength and high-temperature strength of SLS bi-component coated fused ceramic sand was investigated. The action mechanism was explored， and vacuum casting TC4 test was carried out. The results indicate that the initial strength of optimized bi-component coated fused ceramic sand molding with 2% phenolic resin fused ceramic sand + 7% phosphate powder is 0.48 MPa， and the cured strength is 0.73 MPa after low-temperature baking. The high-temperature strength of homemade yttrium oxide coating for baking is 2.64 MPa， and the gassing amount is only 4.16 mL/g. The roughness of titanium alloy castings by vacuum casting is 4.70~8.55 μm without obvious casting defects， and the average microhardness is 371 HV. EDS linear scanning reveals that the average thickness of interfacial reaction layer in titanium alloy castings is less than 30 μm.关键词：Titanium Alloy;Sand Casting;Selective Laser Sintering;Bi-component Binder-coated Fused Ceramic Sand;High Temperature Baking Strength29|39|0更新时间：2025-02-24
Research·Additive Manufacture
- “粉末触变成形工艺制备的50Si/Al-1Mg复合材料，经T6热处理后，抗弯强度和硬度显著提升，热导率变化不大。”摘要：50Si/Al-1Mg composites for electronic encapsulation were prepared by powder thixoforming process， and effects of T6 heat treatment on microstructure， mechanical properties and thermophysical properties of the composites were investigated by determining the thermal conductivity， coefficient of thermal expansion， flexural strength and Vickers hardness. The results indicate that the powder thixoforming process can prepare Si/Al composites with uniform distribution of Si particles and dense structure. After solid solution treatment at different temperatures， the large-sized Si particles grow gradually with the increase of solid solution temperature， and the small-sized ones as well as the second phase are dissolved and finally disappear. After aging at 170 ℃ for 6 h， the flexural strength and hardness of composites reach 387.55 MPa and 256 HV， which are 16.2% and 7.43% higher than those of primary specimens， respectively， while the thermal conductivity has little change.关键词：Powder Thixoforming;50Si/Al Composite;Heat Treatment;Flexural Strength34|20|0更新时间：2025-02-24
- “在材料科学领域，研究者通过液-固复合法制备45号钢/304不锈钢复合管坯，发现浇注温度越高，剪切强度越大。”摘要：The compound tube billet of 45 steel/304 stainless steel was prepared under 1 560， 1 590 and 1 620 ℃ by liquid-solid composite method. The cross-section composites were observed by OM and SEM， and shear strength was tested. The results domestrate that there exists an element diffusion zone at compound interface of 45 steel and 304 stainless steel， and the diffusion zone of Cr and Ni elements is increased with the increase of pouring temperature. SEM observation reveals that compound layers with a certain thickness are generated in all composites. The element distribution becomes more complicated with the increase of pouring temperature， and the element diffusion is obvious. The shear strength of compound interface is 248， 262 and 285 MPa at 1 560， 1 590， and 1 620 ℃， respectively， indicating the enhancement of shear strength with the increase of pouring temperature.关键词：Composites;Pouring Temperature;Shear Strength;Metallographic Structure;Bimetal20|30|0更新时间：2025-02-24
Research·Composites
- “在材料科学领域，研究人员采用激光熔化沉积技术在低活化马氏体/铁素体钢基板上直接沉积W-7Ni-3Fe合金，研究了W/钢接头的组织演变和力学性能。结果表明，制备的W/钢接头呈冶金结合，接头处无裂纹，抗拉强度最高可达557 MPa。”摘要：A laser melting deposition technique was utilized to directly deposit W-7Ni-3Fe alloy on RAFM steel substrate. The microstructure evolutions and mechanical properties of W/steel joints were investigated by OM， XRD， SEM and EDS， micro-hardness and tensile tests. The results indicate that the fabricated W/steel joints exhibit metallurgical bonding without cracks at the joints. The structure of joint is divided into substrate layer， reaction layer， and tungsten alloy layer. Large amounts of Fe7W6 and W particles are dispersedly distributed in the reaction layer， leading to the high hardness up to 662 HV， and the tensile strength of W/steel joint reaches 557 MPa. Due to the presence of plenty of W/Fe7W6 interfaces in the upper part of reaction layer， cracks initiate and propagate in the region， resulting in the final fractures.关键词：W/Steel Joint;Laser Melting Deposition;Intermetallic;Microstructure;Mechanical Properties83|209|0更新时间：2025-02-24
- “在镁合金表面制备羟基磷灰石和聚多巴胺复合涂层，显著提高耐腐蚀性，为稀土镁合金防护提供新思路。”摘要：The hydroxylapatite coating （HA） was prepared on the surface of magnesium alloy samples by hydrothermal method， and then the polydopamine （PDA）/HA composite coating was prepared on the surface by water bath heating method. After hydrothermal treatment， the surface coating of HA single film presents loose with large gaps. PDA/HA composite coating was prepared by PDA coating pre-treatment， whose surface is a uniform cross-covered with small sheet-like structure， showing a complete dense structure. The corrosion rate was calculated by immersion test， and microstructure of the alloy was analyzed by OM. The corrosion behavior and mechanism of the alloy were investigated to evaluate the protective efficiency of the coating. The results indicate that PDA/HA composite coating exhibits better corrosion resistance than single HA coating alloy， and plays a better protective role. The comprehensive properties of PDA/HA composite coatings prepared at 100 ℃ for 4 h are desirable， where the corrosion voltage is 0.063 82 V， and the corrosion current is 8.166 × 10-7 A/cm2.关键词：Magnesium Alloy;PDA/HA Composite Coating;Corrosion Resistance20|38|0更新时间：2025-02-24
- “在激光焊接2mm厚DP780高强双相钢中，不同离焦量对焊接接头成形性和力学性能有显著影响。”摘要：The laser welding test of DP780 high-strength dual-phase steel with thickness of 2 mm was carried out with different defocusing amounts under the laser power of 2 000 W and welding speed of 18 mm/s. By means of metallographic microstructure observation， XRD， EBSD， tensile test and hardness test， the influence of different variables on the formability and mechanical properties of welded joints at defocus from -2 mm to +2 mm was investigated. EBSD results reveal that welded joint is composed of four regions， and there exists thick lath martensite in the weld zone， which are all α phase. XRD diffraction peak presents sharp morphology， and the strong peaks are （110）， （200） and （211）. The tensile strength and elongation of joint is 770 MPa and 12.86% under defocus of -2 mm， respectively， indicating desirable welding. The microhardness of welded joint shows a “M” shape distribution， reaching the minimum value at tempering softening zone.关键词：DP780;Laser Welding;Microstructure;EBSD;Mechanical Property16|38|0更新时间：2025-02-24
- “报道：TC4钛合金经不同温度退火处理后，组织性能变化不大。780℃时，合金组织均匀，力学性能最佳。”摘要：The annealing treatment at 680～830 ℃ was conducted on TC4 titanium alloy with oxygen content of 18%， and the microstucture and properties were investigated. The results indicate that castings suffer a certain degree of recovery under the combined action of internal and external driving forces during annealing， and the variaraion differences in microstructure and performance of castings are relatively small at different annealing temperatures. The structure is evenly distributed buncher composed of α+β+α″ at 780 ℃， where the comprehensive mechanical properties are desirable.关键词：High Oxygen;TC4 Titanium Alloy;Annealing Treatment54|279|0更新时间：2025-02-24
- “在材料科学领域，研究者通过累积叠轧工艺制备异构镁基复合材料，探索了微观组织演变及电磁屏蔽性能，为结构/屏蔽一体化材料开发提供新思路。”摘要：Magnesium matrix heterogeneous materials were prepared by accumulative roll bonding process（ARB）， and microstructure evolution， mechanical and electromagnetic shielding properties of laminated materials with different heterogeneity during the ARB process were investigated. The results indicate that through inserting pure magnesium sheets into AE45 magnesium alloy sheets and rolling， a structure/shielding integrated laminated heterogeneous material can be obtained. During the rolling process， the intermediate layers are subjected to the shear stress， resulting in severe deformation and wavy structure. In the AE45/Mg-C4 material with volume fraction of 29% pure magnesium， conductivity is stable with decrease of pure magnesium volume fraction due to the formation of uniform conductive network with a neatly distributed laminated structure. The laminated heterogeneous material formed by stacking seven layers presents desirable electromagnetic shielding effect in the X-band （8.2~12.4 GHz）. AE45/Mg-C3 exhibits desirable shielding effect of 98.2~109.57 dB in the band of 9.4~10.75GHz. For AE45/Mg-C4 in the 9.4~10.75 GHz band， the desirable shielding effect is 98.2~106.3 dB， and in the 10.75~12.4 GHz band， the satisfied shielding effect is 99.5~109.34 dB， which is attributed to the continuous impedance mismatched interfaces. AE45/Mg-C4 possesses satisfied mechanical properties， where the yield strength， tensile strength， elongation and the hardness reach 245 MPa，316 MPa，20.4% and 106 HV， respectively.关键词：Laminated Heterogeneity;Electromagnetic Shielding Behavior;Mechanical Property;Structure/Shielding Integration22|39|0更新时间：2025-02-24
- “在Al-9Si-2Cu合金领域，研究了不同Fe含量合金在不同时效温度下的微观组织和性能，发现175℃×2h时效处理合金强度最高，达到304MPa。”摘要：Al-9Si-2Cu alloys with different Fe contents （0.2%， 0.5% and 1.2%） were prepared under 75 MPa extrusion pressure and water-cooled quenching conditions， which were subjected to aging treatments of 175 ℃×2 h and 250 ℃×2 h， and effects of aging temperatures on microstructures， mechanical properties， thermal and electrical conductivities of the alloys with different Fe contents were analyzed. The results indicate that the electrical and thermal conductivity of as-cast alloys are lower than those of ones after aging at 175 ℃ for 2 h and higher than those of ones after the aging at 250 ℃ for 2 h. The strength of the alloys after aging at 175 ℃ for 2 h is superior to that of the as-cast ones and the ones after aging at 250 ℃ for 2 h， which reaches 304 MPa. The reason is that the matrix structure of 175 ℃×2 h aging-treated alloy is dominated by G.P. zone， with only a small amount of θ′ phase， whereas G.P. zone disappears in the 250 ℃×2 h aging-treated alloy， and a large number of θ′-Al2Cu phases are precipitated.关键词：Al-Si-Cu Alloys;Aging Treatment;Mechanical Properties;Thermal Conductivity;Electrical Conductivity41|17|0更新时间：2025-02-24
- 摘要：Effects of Sr and ultrasound on solidified structure and mechanical properties of iron-rich A356 alloy were investigated by OM， SEM， EDS， XRD， Brinell hardness tester and tensile tester. The results indicate that Sr and ultrasonic treatment can effectively refine primary grain， eutectic Si phase and iron-rich phase and improve mechanical properties of the alloy. Compared with that of untreated alloy， the length of needle-like iron-rich phase of the composite treated alloy is decreased by 66%， and Brinell hardness， tensile strength， and elongation are increased by 23.1%， 43.5%， and 120.3%， respectively. Under the compound treatment condition， in the range of 0~900 W， grains and eutectic Si phase in the alloy are refined gradually with the increase of processing power，and size of the iron-rich phase is reduced gradually. In the range of 0~90 s， with the ultrasound progressing， grains and eutectic Si phase in the alloy are refined at first and then coarsened and size of the iron-rich phase is decreased at first and then increased with the turning points of 60 s. The mechanical properties of iron-rich A356 alloy are directly retated with solidified structure. With decreasing in the grain size， eutectic Si phase and iron-rich phase of the alloy， the tensile properties and hardness are improved.关键词：Sr;Ultrasonic Composite Treatment;Iron-rich A356 Alloy;Solidified Structure;Mechanical Properties32|34|0更新时间：2025-02-24
- “在铝合金领域，研究者分析了Sb变质对Al-7Si-2Cu-Mg合金显微组织和力学性能的影响，并与Sr变质进行比较，为提高合金性能提供新思路。”摘要：The microstructure and mechanical properties of Al-7Si-2Cu-Mg alloy modified with Sb were investigated and compared with those of Sr modified alloy， and the mechanism was also described. The results indicate that Sb addition can transform eutectic Si in Al-7Si-2Cu-Mg alloy from coarse flake to fine lamellar， meanwhile the eutectic Si can be spheroidized by heat treatment， and the most suitable amount of Sb addition is 0.2%~0.3%. Sb can increase formation temperature of primary α-Al and recalescence magnitude. Sb also reduces precipitation temperature of Q-Al5Cu2Mg8Si6 and θ-Al2Cu， and decrease precipitation amount. The mechanical properties of Al-7Si-2Cu-Mg alloy can be obviously improved by Sb modification， especially the elongation. The elongation of as-cast and T6-treated alloy is significantly higher than that of Sr modified alloy.关键词：Al-7Si-2Cu-Mg;Sb Modification;Microtructure;Mechanical Properties32|42|0更新时间：2025-02-24
- “在材料科学领域，研究者采用受控扩散凝固法制备Al-8Si合金，发现浇注距离80毫米时，合金性能最佳。”摘要：The target alloy Al-8Si was obtained by controlled diffusion （CDS） using pure Al as precursor alloy 1 and Al-12Si as precursor alloy 2 at a certain mass ratio and temperature， and the flow field， temperature field， solute field and nucleation rate of the melt， as well as the experimental grain size and shape of the primary α-Al were analyzed by combination of numerical simulation and experimental verification. The results reveal that the casting distance affects the mixing effect of both master alloys， and when the casting distance is excessive or insufficient， the solute field and temperature field of the mixed melt are heterogeneous with lower nucleation rate， and the primary α-Al presents coarse and irregular grains. When the casting distance is 80 mm， the mixing effect is desirable， and temperature field and solute field are the most uniform with the highest nucleation rate， where the average grain size and shape factor of the primary α-Al are 57.6 μm and 1.55， respectively.关键词：Controlled Diffusion Solidification （CDS）;Al-Si Alloy;Casting Distance;Nucleation Rate;Primary α-Al37|52|0更新时间：2025-02-24
Research·Alloy Performance
- “在材料科学领域，研究者通过X射线显微镜研究了AlZnMgCu合金中孔洞在热处理和压缩过程中的演变规律，发现孔洞形貌受均匀化影响显著，小尺寸孔洞数量增加，大尺寸孔洞在热压缩下逐渐减少，为材料性能优化提供新思路。”摘要：The pore evolution in AlZnMgCu alloy during homogenization heat treatment and hot compression was investigated by X-ray microscopy （XRM）. The results indicate that the pore morphology is greatly affected by homogenization. The micro convex of the dendritic pores and the tortuously narrow connecting channel are coarsened obviously under the drive of Ostwald ripening， resulting in the roundness enhancement of porosities. During homogenization， the number of larger-sized pores as well as three-dimensional size has little change， while the number of small-sized pore is increased. After hot compression at 420 ℃， the number and size of pores are decreased gradually with increase of compression deformation， and the closing rate of pores is increased significantly when the deformation amount exceeds 40%. Pores with the smaller size and shape coefficient tend to be closed， while those with high gas content are diffcult to close， which are finally compressed into smaller spherical ones under large deformation conditions.关键词：AlZnMgCu Alloys;Pore;Homogenization;Hot Compression40|50|0更新时间：2025-02-24
- “在材料科学领域，研究人员通过Mn合金化和1100℃超高温热处理，优化了含碳化物等温淬火球墨铸铁磨球的微观组织和力学性能，显著提高了其硬度和冲击韧度，为工业应用提供了更耐磨、更抗冲击的磨球材料。”摘要：Carbidic Austempered Ductile Iron （CADI） grinding ball exhibits high hardness and high wear resistance and low impact toughness， which is easily broken and leads to failure in practical application. The microstructure and mechanical properties of CADI ball were improved by Mn alloying and 1 100 ℃ ultra-high temperature heat treatment. The results indicate that the microstructure of CADI ball is mainly composed of spherical graphite， carbide， acicular ferrite and residual austenite. With the increase of Mn content， the content of （Fe，Mn）3C in CADI mill ball is increased with the larger size .In addition， the surface and core hardness is increased firstly and then decreased， and the impact toughness is decreased， since （Fe， Mn）3C is transformed from strip to network. When Mn content is 2.1%， the surface and core hardness are 56 HRC and 54 HRC， respectively. The impact toughness is 4.5 J/cm2， and the wear amount is 0.9 mg. After ultra-high temperature treatment， the content of （Fe， Mn） 3C in CADI mill ball is reduced with a smaller size， and the hardness and impact toughness are increased. With 2.1% Mn content， the surface hardness and core hardness are 59 HRC and 56 HRC， respectively. The impact toughness is 6.8 J/cm2 and the wear amount is 0.7 mg.关键词：CADI Grinding Balls;Ultra-high Temperature Heat Treatment;Mn;Impact Toughness20|17|0更新时间：2025-02-24
- “在4Cr13模具钢铸锭凝固领域，专家采用原位熔化冷却法研究了脉冲磁致振荡处理对凝固组织和元素偏析的影响，有效控制了铸锭心部C含量，为提高材料收得率提供解决方案。”摘要：The solidification process of 4Cr13 mold steel is prone to form defects such as shrinkage holes， cracks and macroscopic segregation， which seriously affects the product quality and material yield. The influence of PMO treatment on the solidification microstructure and elemental segregation in 4Cr13 steel ingots under slow cooling conditions was investigated by in-situ melt cooling method. The results reveal that the ingot without PMO treatment iexhibits whole columnar crystal structure with serious center shrinkage and cracks as well as serious elemental segregation. After PMO treatment， shrinkage and cracks in ingot center completely disappear， and the area of equiaxial crystal area reaches more than 50% of the ingot cross-sectional area. C content in ingot core is effectively controlled， which is decreased by 12.94% in the core of 4Cr13 after PMO treatment. Meanwhile， fluctuations of C and alloying elements Si，Cr content are significantly reduced. PMO treatment can significantly refine the dendritic microstructure of 4Cr13 steel， and the length of the primary dendrites is reduced by about 70%.关键词：Pulsed Magneto Oscillation（PMO）;4Cr13 Mold Steel;In-situ Smelting;Center Defect;Solidification Structure;Segregation19|34|0更新时间：2025-02-24
Research·Alloy Process
- “在复杂空心结构铸件领域，专家采用柠檬酸溶液脱除水溶蜡型芯，设计了脱除设备，实现了清洁脱除和环保处理。”摘要：Aming at the difficulties in removing water-soluble wax cores from castings with complex hollow structure and recycle of removed reactants， the removal of water-soluble wax using dilute hydrochloric acid and citric acid solutions was comparatively investigated. The citric acid solution was optimized， and weight of water-soluble wax that can be removed by different concentrations of citric acid solution was tested. The reaction rate and dissolution as well as removal degree of the core were analyzed comparatively. Finally， a process plan for removing water-soluble wax using a 3.4% （mass fraction） citric acid solution was determined. A set of removal process equipment with core removal and cleaning functions was designed， achieving the cleanliness of core removal and physical solid-liquid separation of reaction products， and environmentally-friendly treatment schemes were adopted for solid and liquid products.关键词：Water-soluble Wax;Citric Acid Solution;Investment Casting41|31|0更新时间：2025-02-24
Application·Investment Casting
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