简介:摘要目的探讨磷酸盐包埋材料的不同配比对钴铬合金铸造全冠精密度的影响,提高铸造精密性。方法以磨牙为研究对象制作锥型黄铜帽状试件,以相应的圆柱型黄铜管控制熔模的高度、厚度,高度差为1.8±0.1mm,将嵌体蜡注入得到全冠蜡型。采用无圈包埋法包埋,共分三组,分别为Bellavest快速包埋材料混合液中专用液的比例分别为60%、80%、100%。采用包埋后0.5小时快速升温法焙烧;高频离心铸造、喷砂、就位。用加成型硅橡胶印模材料取得铸件与模具的间隙模型,用金相显微镜观察硅橡胶膜的厚度并拍摄,用金相检验软件系统测量硅橡胶膜的厚度即可得到铸件与模具的间隙值,在硅橡胶代型顶面、轴面分别取点测量硅橡胶膜的厚度;将铸件在模具上就位,用金相显微镜采集图像并测量铸件的边缘浮出量。结果Bellavest包埋料混合液中专用液的比例分别为60%、80%、100%快速升温法三组中,硅橡胶膜的顶面厚度、金属边缘浮出量差别有统计学意义;轴面厚度差别无统计学意义。结论磷酸盐包埋材料的不同配比对铸造全冠的精密度的影响有显著差异。
简介:目的:用热循环法对IPS-EmpressII热压铸瓷嵌体、Brilliant树脂嵌体与金合金嵌体边缘微漏的情况作比较.方法:实验中50个完整离体后磨牙浸泡在生理盐水中三周,每个牙被预备为邻(牙合)洞型,20个无洞斜面,30个有洞斜面.样品被随机分为5组,第1组为瓷嵌体(IPS-EmpressII)用VariolinkII粘结系统粘结,第2组为树脂嵌体(ColteneBrillantcomposites)光/热聚合处理,用OneCoatBond,DuoCement粘结.第3,4,5组为金合金嵌体(Argenco50typeⅣ),分别用松风羧酸水门汀粘固(HY-BondPolycaboxylate)、松风玻璃离子水门汀粘固(HY-BondGlasionomerCX)、登士柏(Poly-F)磷酸锌水门汀粘固.对样本作8℃-60℃300次冷热循环后,样品放在0.5%碱性品红中37C水中恒温24小时,所有样品用金刚砂片沿嵌体长轴作对称性片切,切缘通过修复体近远中中心.在2×15倍立体显微镜下对染色深度作测定,统计学用方差分析法,作F检验和q检验.结果:第1组与第3、4组之间差异无显著性,第1、2组之间差异有显著性,第2、5组与第3、4组之间差异有显著性.结论:热循环处理IPS-EmpressII瓷嵌体的微漏值最小,树脂组的微漏值大于瓷嵌体组及金嵌体.金合金用松风玻璃离子和松风羧酸锌水门汀粘结微漏值比用登士柏Poly-F磷酸锌水门汀粘结微漏值小.
简介:Acomparativestudyofnewmagnesiumalloysdevelopedforelevatedtemperatureapplicationsinautomotiveindustry,Adevelopmentofvirtualprototypingmanufacturingsystemforhighpressurediecastingprocesses,Afinishmachiningstrategyforrapidmanufacturedpartsandtools,Anewmanufacturingtechnologyforinductionmachinecopperrotors,AStudyonPerformanceEvaluationandImprovementofSteeringWheelwithMgDieCastingCore,AstudyonprocessesandmechanicalpropertiesofdiecastA.380V6engineblocks.
简介:HardnessandyieldstrengthincastMg-Alalloys;HEALTHANDSAFETYASPECTSOFINVESTMENTCASTINGWAXES;Highaluminacementsasbindersforinvestmentcastingshells;IIncreaseinCalculationSpeedofRadiativeHeatTransferinPrecisionCastingFurnacesofGas-TurbineBlades;ImprovedCastingProcessforLargeSingleCrystalGasTurbineComponents;IncreasetnCalculationSpeedofRadiativeHeatTransferinPrecisionCastingFurnacesofGasTurbineBlade
简介:Diespray,diecostanddielife;DIE-CASTCOPPERROTORSFORIMPROVEDMOTORPERFORMANCE;DiecastabilityofMg-AI-SrHighTemperatureCreepResistanceAlloysBasedonLaboratoryEvaluations&ComponentDieCastingTrials;Diesandtoolsforhighperformanceapplications;EarlyResidualStressDevelopmentInAluminumDieCastingDies
简介:3DTHERMOMECHANICALSIMULATIONOFTHESECONDARYCOOLINGZONEOFSTEELCONTINUOUSCASTING,4thEuropeanconferenceoncontinuouscasting,Anewprocessofdirectenamelingonvarioussteelgradescoatedwithspecialelectro-depositednickel,Anapproximationmodelofcontactstatebetweenrollandstrand-computationofthree-dimensionaldeformationbehaviorofcontinuouslycaststeelstrandinmultirollspansI,Anelectricdriveforthewithdrawalrollersofacontinuous-castingmachine,Aninvestigationofslagfloatationandentrapmentinacontinuous-castingtundishusingfluid-flowsimulations,samplingandphysicalmetallurgy.