最新刊期
卷 ， 期 2 ， 2004
- 摘要：The age behavior of both as-cast and solid solution tr eated （T6） Al8Si0.4Mg alloys was studied by hardness measurement, differential s canning calorimetry （DSC）, electron probe micro analysis and TEM. Hardness measu rement indicated that as-cast alloy exhibited remarkable age harderning effect, having microhardness peak value lower than T6 treated alloy only by 6 HV. No ob vious effect of cooling rate on age hardening appeared. DSC and TEM analysis results showed that the age hardening for both alloys was attributed to the precipitatio n of metastable β″ and β′phases to strengthen the matrix. The distribution o f precipitated phases and the homogeneity coefficient of mciro-hardnessg for bo th alloys have been discussed.关键词：Al Alloy;Ageing;Precipitated Phase
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发布时间：2023-12-18 - 摘要：The research and application status of semi-solid al lo y rheocasting in about latest 30 years were surveyed. So far due to the storage a nd transport for prepared semi-solid slurry with difficuties, the conventional mechnical stirring technology cann’t still be put into industrial practice. The slurry preparation in injection chamber was introduced. Tensile strength of ca s tings treated by T6 in rheocasting was equivalent to that of castings in squeezi ng casting while the elongation was much higher. Although the single or double s cre w rheocasting injection was characterized by short process, low production cost and low gas porosity, the equipment and technology still need to be optimized. T he technological features and essential principle of tilting plate pouring with low superheated alloy as well as low supreheated alloy with slightly mechanical stirring in semi-solid rheocasting were emphatically discribed combined with the prospec t analysis.关键词：Rheocasting;Semi-solid;Alloy
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发布时间：2023-12-18 - 摘要：The oxidation mechanism of Mg at high temperature and p rotection techniques of present Mg alloy from ignition are briefly reviewed. The principle and technical details of on-line protective atmosphere for Mg alloy are introduced. Continuously quantitative additions of S,C into reactor maintain ed at a given temperature react with clean compressed air to generate protective atmosphere SO 2 and asistant protective atmosphere CO 2 with controllable and adjustable concentration. The results showed that the burning loss rate of liqu id Mg alloy with on-line protection only is 3.8% lower than that wit h SO 2 and FS 6 protection. The on-line protective effects are reliable, avai lable, less expensive for S, C resulting in economic advantages.关键词：Mg Alloy;Anti-ignition;On-line Generation;Protective A tmosphere
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发布时间：2023-12-18 - 摘要：The latest technologies for Al alloy castings with hi gh soundness, mechnical properties and wear resistance as well as large complicate d shape in squeezing casting abroad and at home were surveyed. The partial pr essur ization pressure can be employed to eliminate shrinkage hole and porosity in thi ck position of large complicated parts; the vacuum liquid squeezing casting was suitable for the parts with high soundness and mechnical properties; the Al-Si alloy with high Si content and ceramics reinforced Al matrix composites can be a dopted f or parts with high wear resistance. The core with soluble salt and high collapsi bility was used for the parts with complicated cavities. The squeezing casting w ould be develpoed in practic.关键词：Squeezing Casting;Aluminum Alloy;Composites
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发布时间：2023-12-18 - 摘要：AlTi 5C 0.2 master alloy was prepared by the ex ot hermic dispersive synthesis using Al, Ti and C powders in Al melt. The reactive synthetic process of the master alloy and the generation mechanism as well as r efining fe atures of TiC particulate were investigated by means of OM, XRD and SEM. The res ults showed that the explosively exothermic reaction between Ti（s） and Al（l） for med chunky TiAl 3（s） particle in Al melt at 670 ℃ with elevating the melt tem perature in the reactive zone, and in turn TiAl 3（s） particle dissolved into Al melt to generate active Ti which diffused into the surface of carbon particle t o form TiC particle in coagulative state. The TiAl 3 particle changed from chunky to flaky shapes with obviously clustered TiC distribution with prolonging holding time, resulting in slight reduction of refining performance of the mast er alloy.
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发布时间：2023-12-18 - 摘要：Taking the BMG series as a material system, the physi ca l and structural parameters of the BMG were separately calculated by the additio nal principle, including mixed entropy S mix , mole atomic radius differ ence εd, mole atomic electronic difference εe, thermal diffusion ratio α and ratio （T m/H m） of melting point temperature T m and me lting enthalpy H m. R c（critical cooling velocity）, Z max （ maximum size） and Z max /R c for BMG were considered as the targe t of glass forming abil ity respectively. The statistic figures ε d·ε e ·α·S mix ·T m/H m （denoted by Л）: R c,-Л, Z max -Л ,Z max /R c-Л have been drawn by Origin 6.1 software. The re sults showed that the optimum GFA for Л=0.020～0.175, for Л=0.047～0.1 50 and for Л=0.03～0.15 when R c,Z max and Z max /R c as were taken as the target respectively. The range of c omprehensive optimum Л is 0.047～0.15. It was concuded that the Л was an ideal new paramete r to characterise the glass forming ability of the BMG.关键词：Characteristic Parameter;Bulk Metallic Glass;Glass Formin g Ability;Statistics
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发布时间：2023-12-18 - 摘要：The bonding of explosively welded Cu/50CrV steel bimetal with LD10 Al-alloy mee t by solid\|liquid insert methed.The interface structures of both Al\|steel bime tal and Cu/50CrV steel bimetal were studied and compared by means of SEM.It was found that the Al\|steel bimetel exhibited the wase like structure similar to th at of Cu\|steel bimetal.The structure of Al\|steel bimetal in Al\|matrix zone wa s similar to that of Cu\|bearing Al alloy and in the transitive zone was equival ent to that of disintegrated original Cu\|steel bimetal in the transitive zone and was affected by the structure and phase constituent of Cu\|steel bimetal in the transitive gone.The structure of the broken away grain from steel matrix has bee n greatly changed.The design of explosively welded Cu\|50CrV Steel bimetal shoul d be optimized so as to gain better interface structure.关键词：Explosive Welding;Cast-in Bonding;Interface Structure;D iffusion;Plastic Deformation
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发布时间：2023-12-18 - 摘要：The factors influencing the application of a potenti al dental material should include not only the mechanical property, biocompatili ty, corrosion resistance and cost,but also the casting forming, which has to be excellent and most important for perfect crest making in false tooth casting. B ased on previously developed dental Ti alloy, crest was produced actually by us ing pure Ti casting system. X-ray detection and visual observation indicated th at qualified crest casting free from inner and outer casting defects can meet th e requirement of false tooth casting forming.关键词：Dental Ti Alloy;Tooth Crest;Casting Forming
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发布时间：2023-12-18 - 摘要：Ti-Al base intermetallic compound was prepared by SH S with Ti powder, Al powder and B-Fe as basic raw materials. Effects of SHS techn ique, chemical compositions, B-Fe and charge in preheated furnace at high tempe rature on thermal explosion were researched. The mechanism of thermal explosion and the microstructure of thermal exploded product were analyzed. The results sh owed that the begi nning time of the thermal explosion reduces and the exothermic peak value rose with decrease in Al content and increase in heating rate. The grain refinement c an be realized by restraining the preferable growth of Ti 3Al and delaying the thermal explosion of Ti-Al base intermetallic compound with proper B-Fe additi on. The thermal exploded products consists of needle-like or fine-bar α 2（Ti 3Al） and γ（TiAl） phases.关键词：SHS;Ti-Al Base Intermetallic Compound;B-Fe Alloy
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发布时间：2023-12-18 - 摘要：The in-situ TiB 2 particulate reinforced Al matrix comp osites by mixing-salts reaction were studied. The experimental results showed t hat the microstructure and properties of the composites were wosern with a highe r mass fraction of TiB 2 particulate[w（TiB 2）>8% ]. The mechanism was analyzed systemically from the view of TiB 2 particulate coagulation, segregation and deposition. Th e active Mg addition can improve TiB 2 particulate wettability between and molt en aluminum alloy preventing particulates from coagulation. The segregation and dep osition of t he particulate were restrained effectively with improvement of processing parame ters including high-speed stirring and rapid solidification.关键词：Al Matrix Composites;TiB 2 Particulate;In-Situ Reaction
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发布时间：2023-12-18 - 摘要：Although the research on the mold used for semi-soli d alloy rheological forming is a main part of the semi-solid alloy rheological fo rming,attractive attention hasn’t yet been paid. According to the analysis on th e running principle of mold and the working conditions of ferrous metal in semi -solid rheological forming, it is found that the main failures of mold include thermal fatigue, melt erosion and deformation. It is also pointed out that the k ey properties of mold material include fatigue strength at high temperature, the oxidation resistance and the lower linear expansion rate. With analysis of both advantages and disavatages of conventional mold materials, it is concluded that there aren’t any mold materials suitable for ferrous metal in semi-solid rheol ogical forming at home and abroad now. It is a effective approch to improve the mold service life using composites and surface treatment methodes.关键词：Semi-solid Alloy;Rheological Forming;Mold Material;Ferr ous Metal
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发布时间：2023-12-18 - 摘要：Simulation analysis of mold filling and solidificatio n of the casting was conducted in 4 varieties of gating system with Z-cast softwa re. The optimization and improvement of gating system were done based on analysi s of simulation results to obtain the optimized design sketch. It is found that the use of three chills and proper adjustment of the setting position ca n improve effectively poured quality.关键词：Z-cast;Gating System;Simulation Analysis
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发布时间：2023-12-18 - 摘要：The application of ANSYS general software to numerica l simulation for temperature field during casting solidification was approached. T he numerical simulation on multi-steps sample and actually pouring for Al alloy were respectively conducted. It was showed that numerical simulation results o btained with ANSYS software were well in agreement with actually poured results through establishing suitable mathematical model and setting rational boundary c onditions.关键词：ANSYS;Numerical Simulation;Al Alloy
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发布时间：2023-12-18 - 摘要：Numerous masterpieces in metallurgical technology hav e been deposed in civilization history of China.For thousands of year,the ancient caster not only created countless very great works but also noted many profound technological ideas and design methods.The generalization of engineering technol ogical language in ancient foundry industry,the standardization of denomination and rele vant terminologies in product design,standardization and method of chemical comp osition determination in cast alloy,and the principle and method of parametrizat ion design as well as the idea and method of state in equilibrium and harmony we re discussed in ancient foundry of China.关键词：Nonferrous Alloy Casting;Design Idea;Design Method
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发布时间：2023-12-18 - 摘要：Cu segregation of two varieties of Al-Si-Cu alloy w it h different solidification behaviors under partial pressurization conditions was researched. It was found that Cu segregation of the AC4B alloy with mushy solid i fication was susceptible to negative segregation located below pressurrization b ar and dependant on the time of initial pressurization, while the ADC12 alloy wi th unidirectional solidification only exhibited slightly negative segregation in annular position about 5 mm below pin tip and was not dependant on the time of initial pressurization. In contrast, it presented positive segregation. The Cu segregati on was attributed to the local flow of the condensated liquid through interdendr ite.关键词：Die Castng;Partial Pressurization;Al-Si-Cu Alloy;Negati ve Segregation;Positive Segregation;Interdendritic Liquid Flow
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发布时间：2023-12-18 - 摘要：The present status and developing prospect of die casting market in China were s urveyed.The total turnout of componets in die casting is 0.624 million tons,in w hich Al alloy parts in 0.415 6 million tons,and Zn alloy parts in 0.198 2 millio n tons,and Mg alloy parts is 5 000 tons and 5 300 tons Cu alloy parts in 2002 ye ar.Per year saled die casting machines is about 1 800,in which 2% is l arge machine with above 10 000 kN,38% is middle machine with 3 000～9 000 Kn and 60% is small machine with below 3 000 kN.The total turnout values of die in home is up to 36 billions in 2002 year,in which about 10% is die casting dit.The above 80% die casting enterprises consist of foreign invested enterprises and private enterprises as well as vallages and towns enetrprises and the very large die casting enetrprise group appears.关键词：Die Casting Market;Components in Die Casting;Die Casting Eq uipment;Die Casting Die;Die Casting Alloy
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发布时间：2023-12-18 - 摘要：Silica sol mold shell waste was crushed,magnetic alloy selected and screened out.The phase composition and the pro perties（strength,load ed deformation and permeability）of the reclaimed silica sol mold shell were inve stigated in comparison with that of molochite silica sol mold shell.The results showed that the unbaked mold shell waste can’t be reclaimed and recycled directl y while the used baked poured mold shell waste can be reclaimed and recycled for backing materials of the mold shell.关键词：Investment Casting;Silica Sol Mold Shell;Reclamation and Re cycle
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发布时间：2023-12-18 - 摘要：Structure of colloid aggregation in silic sol was in troduced. The colloid structure consists of colloid core, absorbent layer and di ffusional layer. Moisture in silic sol is composed of free water, absorbent water and structure water. Water-loss rate and range of colloid concretion zon e of silic sol during initial colloid concretion were calculated.关键词：Silic Sol;Colloid Concretion;Water-loss;Structure o f Colloid Aggregation
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发布时间：2023-12-18 - 摘要：Now,sodium silicate binder for mold shell making in i n vestment casting is still widely used. The improved technology for prevention fr om steel leakage in small hole and wash water in surface layer as well as for co ntrolling the shell quality is favorable for the cost drop of raw materials and short ened productive period.关键词：Sodium Silicate Technoloqy;Wax Pattern;Investment Casting
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发布时间：2023-12-18 -
- 摘要：There were 45 reports and three hot points on three E PC syposiums held in America and Germany in 2001-2003:1.Research on elimination of casting defects for Al alloy;2.Improvement of molding tool and of pattern makin g blank;3.An approach to simulation of EPC and rapid prototyping.An introduction of enterpriese status in EPC at home and broad was listed in tables.Three gaps in EPC between China and foreign countries were suggested.关键词：Survey;EPC;Statas Quo
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发布时间：2023-12-18 - 摘要：The proper RE addition to cast Al melt can obviously de crease amounts of gas/pin hole in solidified alloy. It is founded that stable RE -hydride was formed resulting in the decrease of free H content. The RE effects on impurity removal decrease heterogeneous nucleation site of bubble to f urther enhance the gas removal and purification effect.关键词：Cast Al Alloy;RE;RE-rich Phase;RE-hydride;Hydrogen Degassing
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发布时间：2023-12-18 - 摘要：The proper addition of Ce into Z-7 alloy can promote t he refinement of the microstructure and amplitude decomposition effectively so a s to significantly improve the toughness, damping property and wear resistance o f the Z-7 alloy. A new frontier for application of the Z-7 alloy was developed .
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发布时间：2023-12-18 -
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