最新刊期
卷 32 ， 期 11 ， 2012
- 摘要：Preparation of foamed magnesium alloy by two-stage process was conducted, and effects of addition of foaming agent, viscosity-increament agent and Al on structure of foamed magnesium alloy were investigated. Experimental results show that foamed magnesium alloy with uniform structure and high porosity can be obtained by controlling the addition of foaming agent, viscosity-increament agent and Al. With the addition of foaming agent or viscosity-increament agent far more or far less, bubble-free layer and large gas cavity can be observed in foamed magnesium alloy. Heterogeneous structure in foamed magnesium alloy is a common phenomenon without Al addition in melt. With the addition of 2%6% Al, dumping fluidity of melt is improved, and pore size of foamed magnesium alloy becomes homogeneous. With the addition of foaming agent or viscosity-improved agent increases, porosity of foamed magnesium alloy is increased firstly and then decreased. When the addition of foaming agent is 2% or viscosity-increasing agent is 0.1%, the foamed magnesium alloy exhibits desirable porosity. With the increase of the addition of Al in melt, the porosity of foamed magnesium alloy is increased.关键词：Two-Stage Process;Foamed Magnesium Alloy;Structure
- 2
- |
- 240
- |
- 3
发布时间：2023-12-18 - 摘要：Influences of experiment factors on the concretion hardening time, compressive strength at room temperature, flowing radius and foaming capacity in the process of producing gypsum slurry were investigated. The results show that the concretion hardening time of gypsum slurry is proportional to the ratio of water to powder, and the compressive strength of gypsum slurry is improved with adding quartz powder, kaolin, diatomite, sodium chloride and anhydrous magnesium sulfate at room temperature. With the water temperature increases, the concretion hardening time, compressive strength at room temperature, flowing radius and foaming capacity of gypsum slurry exhibit the trend of first decrease and then decrease. Foaming gypsum mold with 80% foaming rate can be made in hard water environment by adding sodium dodecyl sulfate as the vesicant. The foaming of vesicant is inadequate under lower stirring speed and time, while bubbles are easily broken away at high speed stirring and time. The desirable mixing process parameters are 2 000 r/min and 4 min. Foaming gypsum mold was produced based on the optimized process parameter, and then thermal baking was conducted. ZL114A alloy castings were poured at 715 ℃. The results reveal that the parts meet the actual requirements together with broken absence of the foaming gypsum mold in the process of baking.关键词：Gypsum Mold;Foaming;Influencing Factors
- 2
- |
- 144
- |
- 3
发布时间：2023-12-18 - 摘要：<正>令人瞩目的2013新款捷豹·路虎于近期问世,这款车型没有让大家失望。根据市场的发展和需求,此款新车是世界上首台采用全铝硬壳式车身的SUV汽车,新型全铝车身比替换下的钢制外壳减轻39%（约416kg）。新款美版捷豹·路虎采用自然吸气式5升V8发动机,相比前款车型减轻315kg,同时内部空间增大,前后排座椅间距加宽119mm。新型轻量级铝制平台显著提高了汽车操
- 2
- |
- 134
- |
- 0
发布时间：2023-12-18 - 摘要：<正>Bremen Castings公司近期为其机加工车间订购了四台新型机械臂。这家位于美国印第安纳州的灰铁及球墨铸铁件生产企业极为重视工厂的安全生产现状。这家公司在过去的500天中未出现损失工时的事故,此次购进的新型发那科机器人是公司提高企业生产安全性的又一举措。R2000A发那科机器人采用六轴机械组件,是Bremen Castings公司机加工车间重要的自动研磨工具。2011年工厂引进安装的自动机械臂已经证
- 2
- |
- 45
- |
- 0
发布时间：2023-12-18 - 摘要：<正>钢铁行业对能确定热等静压（HIP）的基本质量控制要求的标准存在普遍需求,也因此产生了新的ASTM标准ASTMA1080,即钢、不锈钢和相关合金铸件的热等静压条例。A1080由A01.18铸件委员分会研发,后者是ASTM国际标准组织A01钢、不锈钢与合金铸件委员会的下属机构。John Schleicher是Orchid Orthopedics的技术/发展销售经理,也是A01.18的会员,他表示,热等静压可用于一些合金的特定热处理过程,可减少重复工作并节省时间。此外,HIP处理能改进特定材料的材料性能,在某些应用中,可用于铸合两
- 2
- |
- 85
- |
- 0
发布时间：2023-12-18 - 摘要：<正>就在欧美日通过WTO诉讼对中国稀土政策施压同时,一些产稀土国家稀土开采重启计划也进入了实质阶段。《经济参考报》记者日前采访业内人士表示,包括马来西亚、澳大利亚等国家在内的稀土矿山开发和冶炼等多个项目运行非常顺利,预计下半年将会陆续投产,主要集中在轻稀土方面,不仅产量可观且成本非常低廉,意味着"中国单一
- 2
- |
- 29
- |
- 0
发布时间：2023-12-18 - 摘要：Microstructure, tensile strength and hot cracking tendencies of cast Al-7Zn-2.5Mg-Cu alloy with Al-5Ti-B grain refiner contents including 0, 0.2%, 0.5%, 0.8% and 1.2% were investigated. The results show that grains of Al-7Zn-2.5Mg-Cu alloy are refined obviously by adding Al-5Ti-B grain refiner. With increasing in the refiner addition, the grain size is decreased firstly and then slightly increased. The smallest grain size with 66 μm can be observed with 0.8%grain refiner. As grain size decreases, the number of eutectic is increased, resulting in the improvement of tensile strength and decrease of hot cracking tendencies of cast Al-7Zn-2.5Mg-Cu alloy. Tensile strength and grain dimension follow the relationship of σb=47.227 11+1 325.354 77×d-1/2, and hot cracking tendencies and grain dimension follow the relationship of H=41.739 12+0.573 3×d. Eutectic phase also affects the tensile strength and hot cracking tendency of the alloy. Under experimental conditions, tensile strength is decreased and hot cracking tendency is decreased firstly and then raised with increasing in the eutectic number.关键词：Cast Al-Zn-Mg-Cu Alloys;Grain Refinement;Microstructure;Hot Cracking Tendency;Tensile Strength
- 2
- |
- 146
- |
- 4
发布时间：2023-12-18 - 摘要：Low carbon with 0.2% carbon content and high carbon steel with 1% carbon content were treated by ultrasonic power, and effects of ultrasonic power on solidification structure in carbon steel were observed. The results show that ultrasonic power can refine solidification structure in carbon steel. For low carbon steel, equiaxed grain content is increased and secondary dendrite arm spacing is decreased after treated by ultrasonic treatment. For high carbon steel, net-like carbide is decreased after treated by ultrasonic. Solidification structure in both high carbon steel and low carbon steel is refined with increasing in ultrasonic power, which is attributed to cavitation effect of ultrasonic.关键词：Carbon Steel;Ultrasonic;Solidification Structure;Cavitation Effect
- 2
- |
- 243
- |
- 1
发布时间：2023-12-18 - 摘要：Effects of Sn on the microstructure and mechanical properties of Mg-Zn-Ca magnesium alloy were investigated by alloy preparation, microstructure observation and tensile testing. The results show that with Sn addition, microstructure of the alloy is refined, and phase contained Ca is precipitated from the alloy. With increasing in Sn content, the mechanical properties of Mg-5Zn-2Ca magnesium alloy is increased firstly and then decreased. With 1%Sn addition, the tensile strength and yield strength reach 158 MPa and 123 MPa, respectively, and the elongation is 6.0%. With Sn addition, transformation of fracture morphology can not be observed from SEM.关键词：Sn;Mg-Zn-Ca Alloys;Mechanical Properties;Microstructure
- 2
- |
- 220
- |
- 12
发布时间：2023-12-18 - 摘要：The Glowworm swarm optimization （GSO） program was integrated with Moldflow software in optimization of cooling channel locations at cavity mold and numbers with taking injected mold as an example. Under the condition of setting the maximum cooling channel, the optimized cooling channel numbers and its location were sought automatically, realizing the uniform cooling of the product and improving the cooling efficiency. The maximum distortion and total distortion at the three directions exhibit the minimum value.关键词：Glowworm Swarm Optimization;Moldflow;Cooling Channel
- 2
- |
- 191
- |
- 4
发布时间：2023-12-18 - 摘要：<正>由中国铸造协会主办,中国铸造协会耐磨铸件分会与浙江裕融实业有限公司共同承办的第三届中国耐磨铸件年会定于2012年12月5～7日在杭州市召开。期间同时举行中国铸造协会耐磨铸件分会二届三次理事会、钢铁耐磨材料产业技术创新战略联盟一届三次理事会、第七届全国金属耐磨材料技术及标准化研讨会暨耐磨材料标准审查会、铸造企业的融资与基金公司对接会。
- 2
- |
- 22
- |
- 0
发布时间：2023-12-18 - 摘要：<正>2013南非铸造会议将于2013年3月13～16日在南非西北省Pilanesberg,Kwa Maritane Bush Lodge举行,这在南非尚属首次。为期两天的会议主题将围绕"不断提高的行业竞争力背景下的铸造技术和可行性做法"展开,旨在利用此机会探讨世界范围内铸造和金属铸件领域的前沿技术。本次大会将为行业代表、研究者和大学教师提供一个共享铸造领域先进技术、探讨如何提升行业
- 2
- |
- 28
- |
- 0
发布时间：2023-12-18 -
- 摘要：the status and measurements of casting production management at home were described briefly, and a set of single-part management model was presented. This model could control accurately the whole process of a single casting, including the development, production plan, production acceptance check, delivery and after-sales service, and also could monitor the operational status and the entire production process of a piece so as to eliminate some defects in hand or batch management. Then, a foundry enterprise production management system was developed based on the model. Finally, a practical application case was given.关键词：Single-Castings Management Model;Foundry Enterprise;Production Management
- 2
- |
- 131
- |
- 2
发布时间：2023-12-18 - 摘要：Ni-26Al alloys （ atomic fraction,%） was prepared by laser-induced self-propagating reaction synthesis. Effects of milling time, such as 0,5 and 10 h, on the density、microstructure、composition and mechanical properties of the Ni-26Al prepared were investigated by density measurement, SEM （scanning electron microscope）, XRD （X-ray diffraction） and tensile testing. The results show that the sintered alloy is composed of Ni3Al and γ- Ni 、Al2O3 phases. The sintering performance of the alloy prepared is improved increasing with increasing in milling time, and after 10 h milling, the density, Rockwell hardness and wearing capacity are 5.85 g/mm3 , 62 HRC and 4.43×10-4 g/mm2, respectively.关键词：Laser;Mechanical Alloying;SHS;Ni-Al
- 2
- |
- 79
- |
- 2
发布时间：2023-12-18 - 摘要：The impact and abrasive wear experiments of ZTA/YL302 composites prepared by squeeze infiltration were conducted. The surface morphology of the composites before and after experiment was observed by optical microscopy （OM）and scanning electron microscopy （SEM）. The results indicate that the porosity percentage of ZTA preform reaches 40% 55% with the matrix alloy YL302. Compared with that of the YL302 alloy, the wear resistance of the composite prepared is increased by three times, however, the impact toughness is decreased slightly. The impact toughness of the composites in as-cast state（F） is slightly higher than that in T6 state, and the wear resistance is better than that in T6 treated one.关键词：ZTA/ YL302 Composite;Squeeze Infiltration Casting;Microstructure;Abrasive Wear
- 2
- |
- 103
- |
- 1
发布时间：2023-12-18 - 摘要：<正>MorganMMS是有色金属坩埚领域知名的全球领头羊,为了监督并指导其重要战略区域的快速增长,特聘请张海彬（Michael Zhang）作为MMMS在中国区总经理。张海彬具有丰富的经营管理经验,这次任命将对重申MorganMMS在其关键市场和其他地方的持续增长、产品质量及客户支持的承诺方面起到很大作用。张海彬一直致力于将高绩效团队方法运用于管理。作为中国江苏摩根特种陶瓷技术（苏州）有限公司的总经理,其将负责整个运营活动。主要目标包
- 2
- |
- 21
- |
- 0
发布时间：2023-12-18 - 摘要：<正>锂电池对于大多数人来说并不是什么神奇的东西,但一直以来只能用在手机等小型电子设备上。复旦大学化学系、新能源研究院夏永姚教授课题组采用固相合成技术结合独特的碳包覆技术,成功制备了具有自主知识产权的高电子导电性的纳米钛酸锂材料,将可以用于风能、太阳能储电。据夏永姚教授介绍,以碳为电极材料的传统锂电池,存在一定的安全隐患。近年来,手机电池在
- 2
- |
- 156
- |
- 0
发布时间：2023-12-18 - 摘要：<正>素有"世界锑都"、"江南煤海"、"硅石宝库"等美誉的冷水江市,随着境内资源过度开采,造成空气质量降低、环境污染严重、生态严重破坏,锑都的光芒开始黯淡。作为全国第二批资源枯竭型城市之一的冷水江市,开始了一座工业城市的华丽转身。转身,是一种全新的思考和抉择。善于创造、勇于崛起的锑都人,创造了华丽转身的奇迹!奇迹绽放在大力推进产业规模化、城市生态化、城乡一体化的进程中,灿烂在全方位推进经济转型、生态转型、社会转型、民生转型,努力建设开放文明、殷实和谐、生态宜居的工业新城的收获里。奇迹凸显在"半小时"畅想--由资源独享向"大经济"转身的铿锵前行中。在娄新高速的牵引下,冷水江半小时融入娄底成为现实,飞速推进着冷水江市内"四横四纵"交通网络和建设"半小时快速通勤圈"的构想。
- 2
- |
- 77
- |
- 0
发布时间：2023-12-18 - 摘要：<正>9月27日上午,"宝鸡·中国钛谷"战略规划研讨会在宝钛宾馆召开,标志着"宝鸡·中国钛谷"规划工作正式启动。会上,中国航天材料及工艺研究所、国家工业和信息部运行监测协调局、国务院研究室公交贸易司等专家分别从"宝鸡·中国钛谷"建设概述、钛材应用领域、城市规划等方面作了专题发言。宝钛集团总经理邹武装说,宝鸡作为中国钛工业的摇篮,是国内钛工业的前行者和领路者,更是世界钛工业的重要组成部分。近年来,随着钛产业发展成熟,各地大型钢铁联合企业进军钛材加工领域,对宝鸡钛业带来了大冲击,要突破瓶颈,"宝鸡·中国钛谷"建设就势在必行。邹总经理表示,作为行业的领军企业,宝钛集团将积极投身项目建设,充分发
- 2
- |
- 45
- |
- 0
发布时间：2023-12-18 - 摘要：<正>近年来经过不断发展提升,国内模具企业在积极推进产业优化升级过程中技术水平不断提升,发展规模也日渐增大,中商情报网发布的《2013～2017年中国模具市场发展前景分析报告》数据显示:2012年1～8月,全国模具的产量达958.11万套,同比增长15.98%。8月份,我国生产模具142.48万套,同比增长9.49%。从各省市的产量来看,2012年1～8月,河北省模具的产量达261.57万套,同比下降1.15%,占全国总产量的27.30%。紧随其后的是山西省、
- 2
- |
- 32
- |
- 0
发布时间：2023-12-18 - 摘要：Filling process of magnesium alloy bottom cover with complicated structure was simulated by the Anycasting software to understand entrapment-gas defects in the die castings. The flow behavior of melt during die casting process was visualized to analyze the formation mechanism of entrapment-gas defects. Based on the simulated results, the process was optimized. The filling sequence of melt was modified by decreasing numbers of gate and adjusting filling angle. Through applying optimized design, entrapment-gas can be eliminated effectively, obtaining a desirable filling effect.关键词：Entrapment-Gas;Die Casting;Filling Simulation;AnyCasting Software;Optimization
- 2
- |
- 104
- |
- 14
发布时间：2023-12-18 - 摘要：The microstructural evolution of AZ63 alloy without refining and refined with 1.2% MgCO3 was observed during partial remelting , and its mechanism was analyzed. The results show that both of AZ63 alloys without refining and refined with 1.2% MgCO3 can obtain desirable semi-solid microstructure. The spheroidization rate of AZ63 alloy refined with MgCO3 is increased, which is attributed to the different distribution of β phase in the as-cast microstructure after and before refining treatment. The dendritic arms of specimens without refining become relatively developed, and the area of crystal boundary is comparatively larger, meanwhile, the β phase is more dispersive and almost disappeared in the microstructure with the specimens at eutectic temperature, leading to mergence and growth of adjacent crystal.关键词：AZ63 Magnesium Alloy;Grain Refinement;Partial Remelting;Microstructural Evolution;As-cast Microstructure
- 2
- |
- 83
- |
- 2
发布时间：2023-12-18 - 摘要：Semi-solid 5083 aluminum alloy slurry which treated by self-developed ultrasonic devices with subtended double ultrasonic vibration heads was formed by rheological squeezing casting, and effects of rheological forging process and different pouring temperatures on the microstructure and mechanical properties of the semi-solid 5083 forming parts were investigated. The results show that microstructure of rheological formed semi-solid alloy parts is improved greatly, in which fine, dense and uniform distributed grain can be observed. Mechanical properties of the alloy parts prepared can be increased significantly by power ultrasound and rheological forging process. With the pouring temperature of 645 ℃, the microstructure and mechanical properties of the forming parts become desirable.关键词：5083 Alloy;Semi-solid;Microstructure;Mechanical Properties
- 2
- |
- 128
- |
- 1
发布时间：2023-12-18 - 摘要：The technology and quality layout of a new engine front flange were described, and the control features and measurements in melting 、die casting、 machining、washing and airproof inspect were pointed out. The production of the front flange under rational plan conditions could improve labor rate and decrease the product cost. Meanwhile, the positive effects of control plan and FMEA in producing die casting parts for automobile were expounded. Typical case of die casting technology integrated effectively with management in automobile parts was introduced.关键词：Engine;Front Flange;Die Casting Machine
- 2
- |
- 57
- |
- 1
发布时间：2023-12-18 - 摘要：The factors affecting the performance and fracture mechanism of low-pressure casting A356.2 aluminum alloy wheel spokes were investigated by analysis of secondary dendrite arm spacing, fracture surface and micro-area composition based on testing mechanical properties and observing microstructure of the samples from different shape aluminum alloy wheel spokes. The results show that different type pokes exhibit high strength and low plasticity, in which the yield strength shows relatively steady because it is mainly controlled by the matrix phase state, and the elongation controlled by the internal defects of castings indicates evident change, and the tensile strength exhibits the same trend as the elongation. The impurities and holes are distributed in the tensile fracture surface, and by spectrum analysis, there exists C and O elements at the fracture surface resulted from the dregs and oxide films led by casting process, meanwhile, Fe elements is also relatively aggregated in the spokes. The quasi-cleavage plane and dimple morphology are observed in fracture surface, which shows that fracture mechanism is characterized by the ductile-brittle mixed fracture mode, and the crack is propagated along the eutectic region among dendrite cell.关键词：Aluminum Alloy Wheels;Spokes;Secondary Dendrite Arm Spacing;Tensile Properties;Fracture Analysis
- 2
- |
- 305
- |
- 6
发布时间：2023-12-18 - 摘要：According to the stuctural features of the die casting new-type magnesium alloy steering wheel for the Dongfeng commercial vehicles, the process optimization and the development of the components were conducted with the aid of casting CAE . The casting defects, such as crack,porosity, and formation origination were analyzed. Based on the analysis, casting structure and process were modified. By trial production and the performance testing of the magnesium alloy steering wheel, it was proved that the improvement of the process design and the structure of the casting were effective.关键词：Commercial Vehicle;Magnesium Alloy;Steering Wheel;Die Cast;CAE
- 2
- |
- 120
- |
- 3
发布时间：2023-12-18 - 摘要：Considering structural features and requirements of underwater pump discharge housing, middle-temperature wax was used for making sol silicate shell. Through adopting some technological, such as placing feeding ring on lacy flange , adjusting the flange’s position and height of ingate located inside housing, setting de-waxing holes at crack-easy location, using ceramic core in cavity of shell, re-pouring riser after bottom pouring as well as covering top surfaces of downsprue and riser with asbestos after pouring, the quality of the investment castings fully meet the requirement.关键词：Investment Casting;Processing Design;Feeding Ring;Ceramic Core;Discharge Housing
- 2
- |
- 91
- |
- 0
发布时间：2023-12-18 - 摘要：Stainless steel faucet was produced by investment casting. Through adopting new core making, the core could be cleaned smoothly by shell-vibration and ball throwing. During production process, the shrinkage porosities （holes） could be avoided or eliminated by optimizing assembling-tree design and gating system. After hydraulic examination, the faucet meets the requirements.关键词：Stainless Steel Faucet;New Core;Assembling Tree;Gating System
- 2
- |
- 173
- |
- 2
发布时间：2023-12-18 - 摘要：HT300 automobile mould with 20 tons and 4540 mm in length and 2400 mm in width, 800 mm in height was produced by full mold casting. EPS pattern with 17.5kg/m3 in density and 44.6 kg in net weight was adopted. Common quartz sand with 10/20 mesh was used. And then, three layers water-based coatings with coating thickness of 1.52 mm were sprayed by flow-coating ways, and the pattern was dried at drying chamber for 89 hours. Shower sand-adding combining with man sand-adding was used with negative pressure of 0.05 MPa for 25 min. Medium frequency coreless furnace was adopted to melt iron, and it was poured with bottom pouring integrated with side-pouring at 1 3701 400 ℃ for 3 min. Finally, the dwelling time in the box was approximately 85 hours.关键词：Full Mold Casting;Large Castings;Negative Pressure
- 2
- |
- 72
- |
- 1
发布时间：2023-12-18 - 摘要：For the process of casting accompanied by phase transformation, the vector expression of Langevin radiation pressure gradient was deduced, and the mathematical coupling model of ultrasound field, flow field and temperature field was established. Fluid velocity and temperature distribution were simulated by COMSOL Multiphysics software. The simulated results show that with ultrasonic vibration, melt flow is significantly enhanced, and large flow swirl occurs, which greatly enhance the heat and mass transfer as well as nucleation diffusion. Ultrasonic vibration considerably reduce the temperature gradient of the transition region in the axial direction of round billet, leading to easily forming equiaxed grains.关键词：Ultrasonic Stirring;Casting Process;Numerical Simulation;Non-Isothermal Flow;Coupling
- 2
- |
- 252
- |
- 2
发布时间：2023-12-18 - 摘要：Based on the long time use and development for gravity casting coating, a series of skills and experience of applications of coating in Al piston casting were presented including controlling thickness of coating, dilute ratio of coating, homogeneous coating constituent, cleanness and preheating of the mould and control of temperature as well as spraying ways. The results show that reasonable application of coating can improve casting surface quality and increase casting dimension precision, reducing casting defects and increasing service life of the mould.关键词：Coating;Coating Thickness;Mould Pretreatment;Mould Temperature
- 2
- |
- 103
- |
- 1
发布时间：2023-12-18 - 摘要：There exists three kinds of inclusions, such as long-bar AlN, polygonal Al2O3 phase and near-spherical MnS, in super duplex stainless steel SAF2507 through SEM （scanning electron microscope） observation. The crack is closely related with the excess inclusion content, which has affected greatly the elongation, fracture area rate, resistant fatigue strength. By using water knife cutting technology, crack resulted from the common gas cutting could be avoided, and cut surface exhibited smooth with compact structure.
- 2
- |
- 251
- |
- 2
发布时间：2023-12-18 - 摘要：Zn-1.0Cu-0.2Ti（ZCT）and Zn-1.0Cu-0.2Ti-0.05Mg（ZCTMg） wrought zinc alloys were prepared by melt casting combining with extruding process. Phase compositions, microstructure, tensile behavior and creep behavior of the two alloys prepared were analyzed by OM （optical microscope）, SEM （scanning electron microscope） and tensile testing. Relationship between microstructure and properties of the alloys prepared were described. The results show that both ZCT alloy and ZCTMg alloy mainly consist of η phase、ε phase and TiZn15 phase. Compared with those of ZCT alloy, as-cast microstructure of ZCTMg is refined to some extent, and tensile strength is increased from 212.35 MPa of the extruded ZCT alloy to 248.90 MPa of the extruded ZCTMg. Creep resistance of the ZCTMg alloy is superior evidently to that of ZCT alloy, and the steady-state creep rate is decreased to 3.68×10-7 s-1 from 2.17×10-5 s-1 of ZCT alloy at 130 MPa, which are attributed to nano- TiZn15 phase located at grain boundary and coarse grain size.关键词：Zn-Cu-Ti Alloy;Microstructure;Properties;Tensile Behavior;Creep
- 2
- |
- 237
- |
- 6
发布时间：2023-12-18 - 摘要：Effects of Nd addition on microstructure of as-cast and homogenized ZK60 magnesium were investigated by OM （optical microscope） and XRD （X-ray diffraction）, and influences of homogenizing time on the hardness of the alloy were measured. The results show that Nd can significantly refine grain size in the ZK60 magnesium alloy, reducing the intergranular second phase. Mg12Nd phase can be observed in the magnesium alloy, while it is absent in the homogenized alloy, in which Nd dissolved into the matrix alloy in the form of a simple phase, playing the role in solid solution strengthening. With the increase of Nd content, the solid solution effect is enhanced, and the homogenization time is increased.关键词：ZK60 Alloy;Nd;Vickers Hardness;Microstructure
- 2
- |
- 143
- |
- 1
发布时间：2023-12-18 - 摘要：Effects of precipitates strengthening on vacuum inductive melting copper mould water-cooled casting alloys, such as Al-8.2Zn-2.05Mg（10Zn-2.5Mg, 12Zn-3Mg）-2.2Cu-0.1Mn-0.25Zr, and subgrains strengthening introduced by thermo-mechanical treatment on the Al-8.2Zn-2.05Mg-2.2Cu-0.1Mn-0.25Zr alloy were investigated by optical microscope （OM）, XRD phase analysis, transmission electron microscope（TEM） and tensile tests. The results show that there exist uniform dispersedly strengthening phase η′ in three kinds of alloys with T6 treatment（ageing 120 ℃ at 24 h）, where precipitation strengthening plays a dominant role. With the increase of Zn、Mg content, the amount of precipitated phases is increased gradually, resulting in simultaneous enhancement of precipitation strengthening effect. The tensile strength of the three alloys reaches 646.2 MPa, 697.4 MPa, 732.5 MPa, respectively, corresponding to its precipitation strengthening effect, and the elongation is 13.0%, 10.6%, 7.1%, respectively. Al-8.2Zn-2.05Mg-2.2Cu-0.1Mn-0.25Zr alloy can obtain subgrains structure by using thermo-mechanical treatment including pre-ageing at 120 ℃ for 12 h +30% warm deformation at 120 ℃+final-ageing at 120 ℃ for 10 h , where the strengthening mechanisms of the alloy is characterized by co-action of subgrains strengthening and precipitation strengthening, and tensile strength and elongation reach up to 752.3 MPa and 6.7%, respectively. Subgrains with uniform dispersedly strengthening phases distributing inside are more favorable to the properties of alloy than increasing number of precipitated phases only.关键词：Al-Zn-Mg-Cu-Mn-Zr Alloys;Precipitation Strengthening;Subgrains Strengthening;Microstructure;Mechanical Properties
- 2
- |
- 309
- |
- 2
发布时间：2023-12-18 - 摘要：In order to improve the mechanical properties and casting properties of AZ63 magnesium alloy, different content elements including Y, Nd, Sn and Ca were added. The composition of the new Mg alloy AZ63 optimized by orthogonal experiment is as follows: 0.5%Y, 9.5%Nd, 0.5%Sn and 0.5%Ca. The mechanical properties of AZ63H alloy were tested. The results show that as-cast tensile strength and elongation of the alloy reach 235 MPa and 8.3%, respectively, while after the T6 heat treatment, they are 289 MPa and 11.8% respectively. The new Mg alloy exhibits the better mechanical properties compared with conventional Mg alloys.关键词：Magnesium Alloy;Mechanical Properties;Casting Properties;Orthogonal Testing
- 2
- |
- 107
- |
- 4
发布时间：2023-12-18 - 摘要：A pulsed Nd∶YAG laser was used to modify the surface properties of heat-resistant and high-strength Mg-Gd wrought magnesium alloys with precursor of TiB2 ceramic micro powders and Al powders as the binders. The samples were prepared with different compositions of the precursor in order to understand the effect of TiB2 on the alloying coating. The micro-fine structure, phases constituent and micro-hardness, wear and corrosion resistance of the laser-alloyed layer with different TiB2 content were characterized by SEM （scanning electron microscope）, XRD（X-ray diffraction）, TEM, micro-hardness tester, abrasion testing machine and the Zahner IM6ex electrochemical workstation, respectively. The results show that the in-situ reaction occurs in the alloyed layer between Al and elements of Gd and Y in Mg alloy matrix, and the intermetallic compounds such as Al2Gd and Al2Y with excellent high temperature stability are generated. Meanwhile, the absence of the decomposition of the strengthening phase TiB2 can be observed. The particle size of in-situ synthesized intermetallic compounds and the reinforced phases is about 100 nm and 200 nm, respectively, and they exhibit good compatibility and uniform distribution. However, significant difference in the characteristics of distribution and structures are observed. The overall micro-hardness of the alloyed layer is increased with the increase of TiB2 content and improved up to 46 times of the substrate. However, the friction coefficient and wear weight loss indicate the opposite variation tendency. Compared with the magnesium alloy substrate, the corrosion resistance of the laser surface alloyed samples is improved significantly within a certain range of the composition ratio.关键词：Magnesium Alloy;Laser Surface Alloying with TiB2;Fine Structure;Properties
- 2
- |
- 129
- |
- 1
发布时间：2023-12-18 - 摘要：Based on the practical experience of establishing four art casting laboratories in three different colleges of Guangdong, the development of contemporary art casting’s education was described. By analyzing the reason of the shortage of professionals nowadays and the characteristics of modern foundry industry in Pearl River Delta, it was tried to find out what kind of knowledge structure a modern foundry industry professional should have. Then, from the viewpoint of education, how to combine the art casting laboratory with the creative art casting course as a new teaching pattern was expounded. Finally, to attract more students to study casting technology, training them to be qualified professionals for the modern foundry industry was performed.关键词：Art Casting;Education;Inwestment Casting;Casting
- 2
- |
- 49
- |
- 1
发布时间：2023-12-18 - 摘要：<正>错红铜鸟兽纹壶（见下页）战国（公元前475年～前221年）通高4606cm,质量6.2kg铸造青铜,铸镶红铜保利博物馆藏铜圆壶是周代举行各种礼仪活动时陈设的最重要的盛酒礼器、多作两两成对出现,一盛酒,一玄酒（即新水）,置之尊位,以示尊敬先祖之意。此铜壶壶身和壶盖通体饰红铜纹饰。壶身以对三角形组成格栏、自卜而下分饰七种纹饰,壶盖饰四分式云纹（见图1）。整器纹饰古朴、流畅、华丽,
- 2
- |
- 129
- |
- 0
发布时间：2023-12-18
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0