最新刊期
卷 44 ， 期 1 ， 2024
- 摘要：ZL114A heteromorphic missile shell was manufactured at 715 ℃ by low-pressure filling with filling and solidification time of 4.79 s and 1 615 s， achieving a smooth top-down filling with a top-down and inside-outside solidification sequence. The results indicate that as-cast structure is mostly composed of α-Al matrix， α-Al+Si eutectic， Mg2Si phase， and Al3Ti phase， and average grain size of shell in the top， middle， and bottom regions are 116.09， 147.76， and 178.33 μm， respectively. The mean values of tensile strength， yield strength， elongation and elasticity modulus are 344.66 MPa， 275 MPa， 8.44%， and 71.5 GPa， and dispersion coefficients are 0.55%， 0.93%， 3.5% and 0.7%， respectively. The mechanical properties are declined progressively from top to bottom along the height of the missile shell， and tensile strength， yield strength， elongation， and elasticity modulus in top region are 364 MPa， 284 MPa， 9.2%， and 71.5 GPa， respectively. The morphology of as-cast Si phase is transformed from slatted and blocky shape to a roughly spherical shape after aging heat treatment， with large amounts of residual dimples on the fracture surface， and fracture mechanism is characterized by dimple fracture.关键词：ZL114A;Missile Shells;Heteromorphic;Mechanical Properties;Solidification Forming
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发布时间：2024-01-27 - 摘要：Effects of heat treatment temperature and duration on microstructure， mechanical properties and corrosion resistance of IN718 superalloy were investigated. The results indicate that grain size of the alloy is grade 7～8 with uniform microstructure and absence of defects after heat treatment at 810 °C for 30 min， and desirable comprehensive mechanical properties can be obtained， where the hardness value reaches 250.48 HV， tensile strength is greatly increased by 8.48%， and the corrosion point area reaches the minimum of 1 132.66 μm2. The minimum weight of the alloy after corrosion is 0.001 0 g after heat treatment at 900 °C for 30 min， followed by that of ones at 810 °C for 30 min， which is about 0.001 3 g.关键词：Heat Treatment;IN718 Superalloy;Microstructure;Mechanical Properties;Corrosion Resistance
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发布时间：2024-01-27
Current Recommendation
- 摘要：As a kind of specialty wire with desirable performance， thermal-resistant aluminum alloy wire exhibits technical advantages and wide application prospects in the field of transmission of existing power line corridor and construction of high powder transmission lines. The technical level and future trend of thermal-resistant aluminum alloy conductors were reviewed. The types and performance characteristics of novel thermal-resistant aluminum alloy wires with high performance reinforced core were introduced， and the research direction was put forward.关键词：Thermal-resistant Aluminum Alloy Wire;Al-Zr Alloy;Conductivity
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发布时间：2024-01-27
Research·Review
- 摘要：Owing to the difficulty in defect detection of die-casting， lower detection efficiency and poor working environment， a defect detection software for die casting products based on YOLOX model was developed， and the original data set was enhanced by the data enhancement module in the software， solving the problem of the lack of data set. Then， the Darknet53 structure of YOLOX was skillfully replaced by ShuffleNetv2-plus， and finally improved the average detection accuracy of die-casting part defect based on YOLOX model detection from 86.51% of the original model to 89.19%， which greatly improves the recognition precision of die-casting defects by YOLOX model.关键词：Die Casting Defect;Defect Detection;ShuffleNetv2-plus;YOLOX;Data Enhancement
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发布时间：2024-01-27 - 摘要：To achieve lightweight design of vehicle body， an aluminum alloy steering knuckle solid model was established. The SIMP interpolation model was utilized for multi-operating condition topology optimization， and the structural optimization was accomplished by considering forming requirements of squeeze casting. The results indicate that the maximum stress suffered by aluminum alloy steering knuckle under various operating conditions is significantly lower than yield limit， resulting in a weight reduction of 60.9% compared to the ductile cast iron steering knuckle. After T6 heat treatment， the aluminum alloy steering knuckle exhibits an average tensile strength of 311.03 MPa， yield strength of 252.13 MPa， and elongation of 7.45%， which surpass the specified values， meeting performance requirements.关键词：Topology Optimization;Steering Knuckle;Squeeze Casting;Lightweight
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发布时间：2024-01-27
Research·Computer Application
- 摘要：A non-equiatomic （NiAl）63-xV20Cr17Bx eutectic high-entropy alloy was prepared by non-self-consumable vacuum melting furnace， and effects of B on microstructure and mechanical properties of alloys were investigated by means of XRD， EPMA， and universal experimental machine. The results indciate that （NiAl）63V20Cr17 alloy is composed of B2+BCC dual-phase eutectic structure， which belongs to seaweed-like eutectic dendrites with regular lamellar eutectic surrounded by irregular lamellar eutectic. With the increase in B content， the microstructure of （NiAl）63-xV20Cr17Bx alloys is transformed from the lamellar eutectic structure （x=0） to hypoeutectic structure （x>0.4）， and nanoprecipitates （containing M2B compounds） are generated on primary phase. The hardness of alloy is increased and then decreased， and the fracture strength and fracture strain continue to be increased. When x=0.8， the high entropy alloy exhibits desirable comprehensive mechanical properties， where the hardness， yield strength， fracture strength and fracture strain reach 556 HV， 1 523 MPa， 3 348 MPa and 34.5%， respectively.关键词：High Entropy Alloy;Eutectic Alloy;Microstructure;Mechanical Property
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发布时间：2024-01-27 -
Structure and Propeties of Single-phase Si19.8Ti26.4Cr10.1Mn13.3Fe18.6Ni11.8 High Entropy Alloy AI导读
摘要：The multi-component and single-phase high entropy alloy which is expected to be a high temperature structural material in AlSiTiCrMnFeNi alloy system was developed by trial and error method， and properties were determined by DSC and hardness test. A hexahydric single-phase high-entropy alloy with HCP structure was discovered， of which the composition is Si19.8Ti26.4Cr10.1Mn13.3Fe18.6Ni11.8， and the hardness value is as high as 963.6 HV. The alloy does not undergo phase transition at temperature below 1 400 °C， indicating a stable phase structure， leading to excellent hardness and thermal stability.关键词：High Entropy Alloy;Single-phase;Thermal Stability;HCP- 2
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发布时间：2024-01-27 - 摘要：FeCoCrNiWx high entropy alloys with different W contents were prepared by non-consumable vacuum arc melting furnace. The microstructure， morphology， composition distribution， microhardness， friction and wear properties of the alloy were investigated by X-ray diffraction （XRD）， scanning electron microscopy （SEM）， MFT-EC4000 reciprocating electrochemical corrosion friction and wear tester， microhardness tester and profile tester. The results indicate that FeCoCrNiWx high entropy alloys all exhibit a simple face centered cubic structure （FCC）， which is transformed from a single FCC phase to FCC phase+μ phase with the increase of W content. When x=0.5， the hardness of FeCoCrNiW0.5 is 196.75 HV， and the volume wear has the minumum value. The alloy possesses desirable plastic deformation resistance and wear resistance， and the strengthening mechanism is dominated by solution strengthening and the second phase （μ phase） strengthening.关键词：High Entropy Alloys;Microstructure;Friction Properties
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发布时间：2024-01-27 - 摘要：The effects of TiB2 particles on the microstructure and mechanical properties of TiB2 reinforced AlSi10MnMg alloy casting were investigated. The results indicate that the size of external solidified crystals （ESCs） is decreased and the size and morphology of Fe-rich phases are improved with the addition of TiB2. As a result， the yield strength， tensile strength and elongation of AlSi10MnMg alloy are improved simultaneously. When the content of TiB2 is 0.018%， the yield strength， tensile strength and elongation of the alloy reach 160.5 MPa， 296.3 MPa and 6.7%， which are 5.3%， 11.5% and 115.9% higher than that of AlSi10MnMg alloy， respectively. The tensile fracture observation reveals that there exist many small dimples and few tearing ridges， and the fracture mechanism is dominated by mixed ductile-brittle fracture. With the content of TiB2 further increasing， the number of dimples is reduced， and the proportion of brittle fracture is increased.关键词：TiB2;Vacuum Die-Casting;Microstructure;Mechanical Properties
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发布时间：2024-01-27 - 摘要：The microstructure and phase composition of Zn-9.5Al-3Mg-0.01Ce alloy were investigated by XRD， SEM and EDS. The results reveal that Zn-9.5Al-3Mg-0.01Ce alloy is composed of primary Al dendrites， Al+MgZn2 binary eutectic， Al+Zn+Mg2Zn11 ternary eutectic under cold furnace conditions. The primary Al dendrites are non-single phase， and an obvious step-like morphology is observed at the edges of primary Al dendrites. EDS linear scan results indicate that the Al content at the inner of the dendrites are much higher than that at the external， while Zn content is the contrary， which is attributed to the peritectic reaction during solidification.关键词：Zn-Al-Mg Alloy;Microstructure;Peritectic Reaction
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发布时间：2024-01-27 - 摘要：Fe78Si9B13 amorphous coating was deposited on the surface of ZK60A magnesium alloy by high velocity oxy-fuel （HVOF） thermal spraying. The microstructure of the coating was characterized， and the corrosion behavior of the amorphous coating in SBF （simulated body fluid） was investigated by electrochemical potentiodynamic polarization and impedance measurement. The results indicate that the coating presents dense and uniform with well bonding with the substrate， as well as high amorphous proportion and low porosity. The potentiodynamic polarization test results reveal that the corrosion rate of the coating is far lower than that of the magnesium alloy matrix， and lower than the upper limit of the degradation rate of the two stages before bone defect repair. The impedance spectrum analysis results coincide with the polarization curve， and the corrosion resistance of the coating in SBF is significantly higher than that of the magnesium alloy matrix.关键词：ZK60A Magnesium Alloy;Fe-based Amorphous Coating;Electrochemical Test;SBF
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发布时间：2024-01-27 - 摘要：The microstructure and properties of 6061 aluminum alloy were modified by adding Sc. 6061 and 6061-0.2Sc ingots were prepared by vacuum induction melting and homogenized and annealed at 550 ℃×12 h， followed by hot extrusion deformation and solution aging heat treatment of 570 ℃×1 h water quenching +175 ℃×5 h air cooling. The microstructure and properties of Sc microalloyed aluminum alloy sheet before and after extrusion were invstigated. The results indicate that Sc has grain refinement effect， and the grain size of 6061-0.2Sc is 20~50 μm after homogenization. The grain size of 6061-0.2Sc after extrusion and solution aging heat treatment is finer and more uniform than that of 6061 alloy. After Sc addition， the tensile strength and elongation of the alloy are improved， and the macro fracture is smooth， and the tensile fracture mode is converted from tough-brittle mixed fracture to ductile fracture.Mean-while， the corrosion current density is decreased from 946.62 μA/cm2 to 568.05 μA/cm2， indicating the significant enhancment of corrosion resistance.关键词：Aluminum Alloy;Rare Earth;Extrusion Deformation;Mechanical Properties;Corrosion Resistance
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发布时间：2024-01-27 - 摘要：In order to explore the influence of counpound addition of trace element on the size， morphologies and mechanical properties of Al-Si grains， Al-8Si-0.6Mn-0.4Mg-0.15Ti-xSc （x=0， 0.2， 0.4， 0.5，%） alloys were prepared by melting-casting， and the morphology， size， strength and tonghness of alloys were characterized and analyzed by metallographic structure diagram， scanning electron microscopy， and energy spectrum. The results indicate that the main phase of as-cast Al-8Si-0.6Mn-0.4Mg-0.15Ti-xSc alloy includes α-Al matrix， eutectic Si phase， Al3Ti， Al3Sc， AlMnTi， and Fe-rich phase. When the Ti content is 0.15%， alloy with the desirable grain refinement effect can be obtained by adjusting the Sc content to 0.2%， where the average grain size is 46 μm， tensile strength reaches 221 MPa， and elongation is 5.9%.关键词：Al-Si Alloy;Microstructure;Compound Addition;Mechanical Properties
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发布时间：2024-01-27 - 摘要：The effects of Sn and Ca content on microstructure and mechanical properties of Mg-Sn alloy by squeezing casting were investigated. The results indicate that with the increase of Sn content， the grain of Mg-Sn alloy is refined， and the amounts of Mg2Sn phase are gradually increased， so the mechanical properties of the alloy are improved， and the performance reaches desirable when the Sn content is 5%. When Ca content is below 1%， with the increase of Ca content， the grains of Mg-Sn-Ca alloy are significantly refined and Ca-Mg-Sn phase can be generated， so the mechanical properties of the alloy are gradually improved. When the Ca content is more than 1%， the second phase is coarsened and agglomerated in the alloy， resulting in a decrease in properties of the alloy.关键词：Magnesium Alloy;Squeezing Casting;Microstructure;Mechanical Properties
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发布时间：2024-01-27 - 摘要：The effects of Sc alloying on microstructure evolution and mechanical performance of Al-Li-Cu-Mg alloy were investigated. The results indicate that 0.2% Sc addition has significant effect on grain refinement of the alloys. Meanwhile， Sc alloying obviously enhances the precipitation density of the core/shell composite particles in as-aged alloy. Sc-containing alloy exhibits excellent matching of strength and plasticity at room temperature and 200 ℃， which is attributed to the synergy of the grain refining strengthening and precipitation strengthening （δ′-Al3Li phase and core/shell composite structure particles）. When the temperature is increased to 300 ℃， the strength of Sc-containing alloy is decreased sharply， while elongation is increased significantly due to the grain boundary weakening effect. The fracture morphology observation reveals that the fracture mode of the reference alloy presents quasi cleavage fracture at room temperature， which is stable with the variation of temperature. The fracture mode of Sc-containing alloy at room temperature is characterized by intergranular fracture， which is transformed to mixing fracture of intergranular and transgranular at 200 ℃， and microporous aggregation fracture at 300 ℃.关键词：Cast Al-Li Alloy;Sc Alloying;Mechanical Properties;Fracture Mode
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发布时间：2024-01-27 -
Effect of Wall Thickness on Microstructure and Mechanical Properties of Al-5.8Zn-2.3Mg-1.7Cu Alloy AI导读
摘要：The influence of wall thickness （5， 15， 30 and 60 mm） on microstructure and mechanical properties of Al-5.8Zn-2.3Mg-1.7Cu alloy was investigated by optical microscope， scanning electron microscope， Brinell hardness tester and universal material testing machine， combined with self-designed low pressure casting step mold. The results indicate that the microstructure of the alloys with different wall thicknesses is significantly different， where the regions with thinner wall thickness is finer， and the width of intergranular eutectic microstructure becomes narrower with the increase of cooling rate. The mechanical properties of the alloy are increased firstly and then decreased with the increase of wall thickness， achieving optimal results at the thickness of 30 mm， where the hardness， tensile strength and elongation reach 118 HBW， 300.26 MPa and 7.55%， respectively. The fracture morphology of the alloy is dominated by dimple and cleavage plane.关键词：Al-5.8Zn-2.3Mg-1.7Cu Alloy;Casting Wall Thickness;Microstructure;Mechanical Properties- 30
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发布时间：2024-01-27
Research·Alloy Performance
- 摘要：The defect morphology of ingots and alloy strip fabricated by different casting methods were investigated by optical microscopy（OM） and field emission scanning electron microscopy （FESEM）. 3D detection of defects were analyzed by CT V/Tome x m with resolution of 20 μm. The results indicate that the grain of ingot by the modified casting process of double water-cooled ring is obviously refined with dimension of 15 mm， and fraction of columnar crystal region is relatively low， while that of equiaxed crystal region is large. CT3D detection and microstructure observation reveal that large quantities of defects are distributed in network by conventional casting method， with dimension of 0.599 mm， while those by improved casting are dipersively distributed with dimension of 0.161 mm. The particle phases and stripe in defects of copper strip foaming， peeling and delamination are basically the same as those in as-cast defects， which are caused by shrinkage defects in the ingot， indicating the necessity to reduce shrinkage defects in the ingot.关键词：C19400 Alloy;Casting Process;Defect Morphology
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发布时间：2024-01-27 - 摘要：Taking “⊥” shaped and rod-shaped specimens as examples， the effect of casting process parameters on the filling behovior and solidification structure of ZL205A alloy castings under counter gravity conditions were investigated. The results indicate that thin-walled castings with an average wall thickness less than 3 mm exhibit desirable formability due to the smoother filling process of counter gravity differential pressure casting， while sharp corner structures cannot be achieved. Increasing the pouring temperature or mold temperature can improve the filling performance of differential pressure casting thin-walled ZL205A alloy castings， and the former one has a more significant effect than the latter. Compared with low-pressure casting， differential pressure casting can significantly refine the grain size of ZL205A alloy， and increasing the pouring temperature or mold temperature can appropriately further refine the grain size， and the former one has a more significant effect than the latter. For ZL205A alloy castings with a certain cross-sectional thickness， when the cross-sectional thickness exceeds a certain amount， the filling performance is less affected by the mold temperature and gating system design during differential pressure casting， and increasing the mold temperature leads to more porosity defects in castings.关键词：Differential Pressure Casting;Filling Performance;Solidification Structure;ZL205A Alloy
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发布时间：2024-01-27 - 摘要：Effects of hot-pressing temperature on interlayer width of gradient high-silicon aluminum alloy were investigated， and the thermal stress distribution in gradient high-silicon aluminum alloy as well as effects of interlayer width on thermal stress were conducted by finite element simulation. The results indicate that as temperature rises， the interlayer undergoes transformation from a clear interface to a fuzzy interface， and finally vanishes， which promote the diffusion of silicon at the boundary. According to the simulation results， the average thermal stress of Si/Al alloy is increased with the interlayer width. The average thermal stress of Al matrix phase is greater than that of Si matrix phase， while the extreme value of stress mainly appears in the silicon phase.关键词：Numerical Simulation;High-silicon Aluminum Alloy;Gradient Structure;Thermal Stress
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发布时间：2024-01-27 - 摘要：The scaling layer on the surface of a SCR 7000 casting wheel crystallizer was analyzed by SEM， EDS and XRD， and the scaling mechanism was investigated combined with the interaction between spray cooling water and high temperature casting wheel. The results indicate that the scale layer in the groove of inner cavity of crystallizer is composed of carbon black， Cu， Cu2O and CaO， which is formed by the combination of enrichment of carbon black generated by incomplete combustion of acetylene， concentration and precipitation of CaCO3 in the slag flushing water， high-temperature decomposition， and high-temperature diffusion of Cu crystallizer and copper billet. The scale layer at the bottom and outside of the crystallizer is mainly composed of CaCO3， which is attributed to great hardness of spray water caused by evaporation of cooling water and insufficient water treatment capacity. CaCO3 crystals are supersaturated and precipitated on the surface of the high temperature casting wheel， and CaCO3 particles attached to the spray water film at the bottom of the circular motion casting wheel are subject to centrifugal force， accelerating the formation of CaCO3 crystal scale. The difference in the phase， thickness and uniformity of scale layer on each side of crystallizer leads to the abnormal solidification structure of inverted trapezoidal copper billet. By reducing the hardness of the turbid circulating water and adopting the technology of flushing slag with clean circulating water， the scaling degree of casting wheel and the solidification structure of the copper billet is significantly improved.关键词：Casting Wheel Crystallizer;Solidification Structure of Copper Billet;Scaling Mechanism
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发布时间：2024-01-27 - 摘要：Taking the automobile differential supportor as object， the microstructure and mechanical properties of AZ91D alloy were investigated under different near-liquidus squeeze casting temperatures. The results indicate that when the pouring temperature is increased from 595 ℃ to 665 ℃， the spherical crystal in the alloy is gradually transformed into a rosette-like crystal， and the average grain size is increased from 21.02 μm to 58.13 μm. The content of the second phase β-Mg17Al12 is increased from 18.55% to 49.72%， and its uniformity is gradually weakened. When the pouring temperature is low （595 ℃ and 605 ℃）， there exist a lot of dimples and a small area of cleavage plane in the tensile fracture. The number of dimples and cleavage steps of the fracture is gradually decreased at a higher pouring temperature. At the pouring temperature of 605 ℃， the tensile strength and elongation reach up to 229.2 MPa and 3.16%， respectively.关键词：Pouring Temperature;Near-liquidus Squeeze Casting;AZ91D Mg Alloy;Microstructure
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发布时间：2024-01-27
Research·Alloy Process
- 摘要：The influence of TiB2 particles on aging behavior and mechanism of particles promoting aging precipitation were systematically explored by comparing aging behavior of in-situ TiB2 particle reinforced aluminum matrix composites and matrix alloy. The variation of tensile properties and hardness of TiB2/Al-4.5Cu composites and matrix alloy during the aging process were investigated. The results indicate that TiB2 particles can accelerate the aging process of the composites， while high-density dislocations near TiB2 particles lead to uneven precipitation of Al2Cu phase. Compared to the matrix alloy， the peak aging time of TiB2/Al-4.5Cu composite is shortened from 20 h to 8 h. Mechanical property variation of the composites with aging time can be divided into two stages， which is consistent with the transformation in Al2Cu precipitates. The yield strength of composites is increased by 24% compared to that of one before aging， and increased by 82% compared to that of aged matrix alloy.关键词：Metal Matrix Composites;Aging Behavior;TiB2 Particles;Al2Cu Precipitate;Mechanical Property
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发布时间：2024-01-27 - 摘要：TC4/Al3Ti micro-laminated composites were prepared by high vacuum hot pressing taking TC4 foil and pure Al foil as raw materials， and the influence of component layer thickness on the microstructure and properties of the composites was investigated. The microstructure， crack fractures were analyzed by metallographic microscopy， X-ray diffractometer， scanning electron microscopy， and field emission electron probes. The results indicate that with the constant thickness and volume fraction of Al3Ti in the specimen， the smaller the component layer thickness， the better the mechanical properties. When the number of laminated layers is 55， the component layer thickness is the minimum， and the performance is optimal， where the flexural strength is 970 MPa， the compressive strength perpendicular to the layer is 1 307 MPa， and that parallel to the layer is 1 206 MPa.关键词：Al-Ti Microlaminated Composites;Vacuum Hot Pressing;Mechanical Properties;Fracture Morphology
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发布时间：2024-01-27 -
Microstructure and Mechanical Properties of SPS Diffusion-bonded Interface of Diamond/Cu Composites AI导读
摘要：SPS diffusion bonding tests were carried out on the diamond/copper composite， and the interface diffusion analysis and shear performance test were conducted on the joints. The effects of SPS diffusion bonding process parameters on the microstructure and mechanical properties of the bonding interface were investigated. The results indicate that with the increase of bonding temperature and sintering time， the defects such as holes and voids in the diffusion interface area of diamond/copper joint are decreased， and the element diffusion is sufficient with tungsten gradually diffusing to the copper direction， and the W2C phase and W phase in the bonded interface are reduced compared with the base metal. With the improvement of diffusion bonding quality， the thermal conductivity， maximum shear force and shear strength of bonded joints are increased， and a large number of cleavage planes and fracture steps are gradually generated on the shear section， accompanied with a small number of tear edges. The fracture mechanism is transformed from brittle fracture to semi-cleavage ductile fracture. When the diffusion temperature is 750 ℃ and the sintering time is 90 min， the bonding interface presents a satisfied element diffusion effect and maintains a high thermal conductivity［347.73 W/（m∙K）］， where the maximum shear strength reaches 48.83 MPa.关键词：Diamond/Cu Composites;SPS;Interface Bonding;Mechanical Properties;Thermal Conductivity- 1
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发布时间：2024-01-27
Research·Composites
- 摘要：Three groups of vacuum die-casting experiments for AZ91D magnesium alloy were carried out with a self-designed vacuum pumping system to investigate the effects of different rapid injection speeds on the mechanical properties and microstructure of vacuum die-casting parts. The results indicate that the die castings fabricated by the vacuum pumping system exhibit complete shape and the better mechanical properties than ordinary die castings. When the rapid injection speed is 3 m/s， the surface of the die castings is easy to form cold shut and flow marks， and there are many shrinkage porosity and holes in the microstructure. When the rapid injection speed is 5 m/s， the die castings are prone to flash and there are many shrinkage holes in the microstructure. When the rapid injection speed is 4 m/s， the die-castings have a complete shape with a few shrinkage cavities in the microstructure. The tensile strength and the elongation of the heat sink reach up to 226 MPa and 5.4%， respecively.关键词：Magnesium Alloy;Processing Parameter;Vacuum Die Casting
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发布时间：2024-01-27 - 摘要：Based on 9AT transmission housing， filling simulation was carried out for the die-casting process of the main housing and the influence of high and low speed switching positions on the flow and filling of the metal fluid was analyzed. The results reveal that with the low speed of 0.2 m/s， the high speed of 3.5 m/s and the switching position of 560 mm， the filling flow is smooth and the probability of gas-entrapment is the lowest. The optimized process parameters were adopted for the trial production， and products are dense with the satisfied mechanical properties.关键词：Die Casting;Transmission Housing;Simulation;Mechanical Properties
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发布时间：2024-01-27
Application·Die Casting
- 摘要：In view of problems of equipment in the workshop of investment casting enterprises， heterogeneous data transmission protocol and storage structure， difficulty， disorder and missing in heterogeneous data collection， a data acquisition and management framework for workshop production and equipment resources was proposed. Based on perception processing strategy of multi-source heterogeneous data in the workshop， the data transmission route was designed， and the characteristics of poor data interaction between devices and difficulty in perception processing were solved. Combined with principal component analysis （PCA） and long short term neural network （LSTM） algorithm， a prediction model for variation law of workshop production was established， and processing as well as analysis prediction of data were completed. Finally， the workshop data acquisition and management framework were utilized to achieve acquisition of 28 processes and site data， where the minimum acquisition interval can reach 1 000 ms， and 5×105 data can be collected per day. The prediction model of casting production was built， with the average absolute error of 0.046 2% and determination coefficient of 0.915 2， indicating desirable generalization.关键词：Casting Workshop;Data Acquisition;Neural Network;Investment Casting
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发布时间：2024-01-27
Application·Investment Casting
- 摘要：Matte often occurrs in bright pure silver jewelry blank during the middle annealing， which increases the subsequent polishing workload. Taking sterling silver commonly used in jewelry industry as raw material， the annealing process of bright silver bars was analyzed in the atmosphere. The results indicate that with the extension of annealing time， the hardness is decreased rapidly at first and gradually tends to be stable. The chromatic aberration is constantly increased， presenting the pattern of “fast followed by slow”. With the increase of heating temperature， the decreasing rate of hardness is raised， and the final hardness value is low， while the chromatic aberration is increased correspondingly. Therefore， a proper balance needs to be kept between hardness loss and color retention of bright pure silver annealed in the atmosphere. For bright silver bars for bangles with medium thickness， the annealing temperature is controlled at 400 ℃ for about 60 min， which can basically meet the needs of hardness reduction and brightness retention.关键词：Pure Silver;Bright Annealing;Hardness;Chromatic Aberration
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发布时间：2024-01-27
Application·Art Casting
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