快速制造粘土类陶瓷原型工艺研究1

快速制造粘土类陶瓷原型工艺研究1-I-快速制造粘土类陶瓷原型工艺研究1摘要快速模具制造技术是20世纪80年代后期产生并发展起来的一种新型制造金属模具技术，它在制造特别复杂型腔模型的金属模具上大大缩短了模具产生的周期，降低了开发成本，在效率和精度方面优势明显。等离子熔射快速模具制造是快速模具制造技术的一种制模方法，它属于间接制模的一种，因其几乎不受制模材料和尺寸大小的限制，模具尺寸及表面精度高而被广泛采用。在等离子熔射制模工艺中，耐高温原型的获得一般是从硅胶模翻制而来，而硅胶模又是从快速制模的原型翻制得到的，两次翻制工艺会损失一定精度并耗费较多时间。本研究采用数控机床直接铣削粘土原型工艺，减少了上述工艺两次翻制的弊端。但是在铣削后获得的原型还需要加热烧结获得耐高温原型，在烧结冷却过程中，粘土原型会发生先膨胀后收缩，到最后粘土原型会出现收缩。烧结工艺作为把粘土原型转变为陶瓷原型的一个关键工艺，其工艺质量的高低很大程度上影响到耐高温陶瓷原型表面尺寸精度。由于陶瓷原型硬且脆，精加工时容易形成崩豁且加工成本很高，为了尽量减少精加工时的去除量，研究粘土原型在加热烧结过程中尺寸变化即收缩率机理就显得尤为重要，由此引申出的尺寸补偿和参数化建模问题则考虑的是如何通过已知的陶瓷原型的尺寸来逆向反求出未知的粘土原型的尺寸以及在Pro/E制图软件上如何实现相关建模的操作。金相图样分析表明，粘土原型经过精加工后表面精度可达到1m，已经满足后续等离子喷涂工艺的要求，不需要后续精加工了。但如果是加工陶瓷零件，考虑到表面精度要高的问题则还需要做磨削精加工，为此本文简略介绍了磨削相关理论和模型，并结合机器人自动抛光系统进一步论证其加工的可行性。关键字：快速制造；烧结工艺；尺寸补偿；参数化建模；磨削机理；机器人自动抛光华东交通大学毕业论文-II-ProcessresearchIIofRapidManufacturingCeramicPrototypingofClayABSTRACTRapidtoolingtechnologyisinthelate1980sanddevelopedanewtypeofmanufacturingmetalmolds,ithasobviousadvantagesinefficiencyandaccuracy,particularlyincomplexcavitymodel,duetogreatlyreducingthecycleofthemold,reducingdevelopmentcosts,Rapidtoolingbyplasmasprayingisarapidtoolingtechnology,anindirectmoldingmethod,itiswidelyusedbecauseitisalmostfreefromthemoldingmaterialandthesizelimit,thediesizeandhighsurfaceaccuracy.Plasmaspraytoolingprocess,thehightemperatureprototypeforgeneralreproductioncomesfromthesiliconemold,siliconemoldfromrapidtoolingprototypereproduction,twicethereproductionprocesswilllosesomeaccuracyandspendmoretime.Inthisstudy,theuseofCNCmachinetoolsmillingclayprototypeprocess,reducingthedrawbacksoftheaboveprocesstwicereproduced.Obtainedaftermillingprototypeheatsinteringtoobtainhigh-temperatureprototypeshrinkageaftersinteringcoolingprocess,theclayprototypeofthefirstexpansioninthelastclayprototypetherewillbeshrinkage.Thesinteringprocessasacriticalprocess,thelevelofthequalityoftheprocessgreatlyaffectedtheprototypehigh-temperatureceramicsurfacedimensionalaccuracyoftheclayprototypeintoaceramicprototype.Easytoformhardandbrittleceramicprototypes,finishingcollapseexcludedandthemanufacturingcostishigh,itisparticularlyimportantinordertominimizethefinishingtimeofremovalofclayprototypeindimensionalchangesintheheatingduringthesinteringshrinkagemechanism,whichcomeoutofthesizeofthecompensationandparametricmodelingtoconsiderishowthesizeoftheceramicprototypeknownanti-reversetofindtheunknownsizeoftheclayprototypeaswellashowtheoperationoftherelevantmodelinginPro/Edrawingsoftware.Themetallographypatternanalysisshowedthattheclayprototypesurfaceaccuracyafterfinishingcanbeachieved,theyhavemettherequirementsofthefollow-upplasmasprayingprocess,nofollow-upfinishing.Processedceramicparts,takingintoaccountthehighsurfaceaccuracyyouneedtodothegrindingfinishingthispaper,abriefdescriptionofthegrinding-relatedtheoriesandmodels,combinedwiththerobotautomaticpolishingsystemfurtherdemonstratedthattheprocessingviablesex.Keywords:RapidManufacturing;Roastingprocess;Dimensioncompensation;Parametricmodeling;GrindingMechanism;Automaticpolishingrobot快速制造粘土类陶瓷原型工艺研究1-III-目录摘要.........................................................................................................I第一章绪论............................................................................................11.1选题背景及目的..................................................................................................................11.2国内外研究概况..................................................................................................................11.3对于尺寸补偿和参数化建模的个人理解...........................................................................41.4本文的主要工作..................................................................................................................4第二章粘土原型加热烧结工艺.................................................................52.1粘土原型加热收缩特性......................................................................................................52.2烧结工艺简介......................................................................................................................52.3烧结工艺实验.......................................................................................................................62.3.1前期准备工作和设备仪器简介............................................................................62.3.2烧结实验过程........................................................................................................72.4测量粘土原型材料在空间三个方向上的收缩率.............................................................102.5尺寸补偿和参数化建模.....................................................................................................112.5.1粘土原型材料在空间三个方向的补偿量..........................................................112.5.2粘土原型的参数化建模......................................................................................12第三章陶瓷原型磨削工艺........................................................................173.1陶瓷原型磨削工艺概述..................................................................................................173.2陶瓷磨削过程及表征工件加工性能的磨削参数.............................................