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1、河北工业大学硕士学位论文外送粉电弧喷涂复合涂层工艺与性能的研究摘要目前电弧喷涂复合涂层主要使用粉芯丝材,但粉芯丝材存在成本高的问题。本文针对此问题提出了外送粉电弧喷涂技术的概念,成功地利用实心丝材制备出复合涂层,并利用正交试验、SEM和XRD等试验方法,对复合涂层的组织、结合强度、显微硬度和耐磨性进行了研究。电弧喷涂复合涂层为典型的层状结构,主要由铁铬化合物、铁的氧化物、氧化铝组成。喷涂电流、喷涂距离和雾化空气压力对涂层的质量都有着重要的影响,过大或过小的喷涂参数都影响着复合涂层质量的好坏。影响复合涂层结合强度的工艺参数由主到次依次为喷涂电流、雾化空气压力、喷涂距离和喷涂电压。喷涂工艺
2、参数对涂层显微硬度影响由主到次是喷涂距离、雾化空气压力、喷涂电压和喷涂电流。在低于450℃热处理时,复合涂层与基体的结合强度略有所提高,在高于450℃热处理时,复合涂层与基体间的结合强度显著降低。随着复合涂层厚度的增加,结合强度有所降低。在干摩擦条件下,随喷涂电流和雾化空气压力的增加,复合涂层磨损失重下降,而随喷涂电压和喷涂距离的增加,磨损失重均呈上升的趋势。复合涂层的磨损机制主要为硬质颗粒的脆性脱落,同时伴随着轻微的显微切削。关键词:电弧喷涂,外送粉,结合强度,显微硬度,耐磨性i外送粉电弧喷涂复合涂层工艺与性能的研究TECHNOLOGYANDPROPERTYOFCOMPOSITECO
3、ATINGBYARCSPRAYINGFEEDINGFROMOUTSIDEABSTRACTNowadaysarcsprayedcompositecoatingsaremostlypreparedbycoredwires.Butthehighcosthasrestrictedtheirapplication.Inthispaper,wehavegiventheconceptionofoutside-feedingarcsprayingtechnologyandpreparedcompositecoatingsbysolidwires.Structure,combiningintensity
4、,microstructure,andwearresistanceofthecoatingsarecharacterizedbytheorthogonaltest,SEM,andXRDetc.Arcsprayedcompositecoatingsarecomposedofiron-chromiumcompounds,ironoxide,andaluminumoxidewithlayeredstructure.Qualityofthecoatingsiscloselyrelatedtothesprayingcurrent,distance,andpressureoftheatomizin
5、gair.Greatqualityofthecoatingscannotobtainedunderabiggerorlowerparameter.Technicalparameterswhicheffectthecombiningstrengthofthearcsprayedcoatingare(frommaintominorinturns)sprayingcurrent,atomizingairpressure,sprayingdistance,andsprayingpotential.Themicro-hardnessofthecoatingsareeffectedby(fromm
6、aintominorinturns)sprayingdistance,sprayingpotential,atomizingairpressure,andsprayingcurrent.Combiningintensityofthecoatingandthesubstrateisincreasedwhenheat-treatedunder450℃.Butwhenthetemperatureenhancesabove450℃,thecombiningintensitydecreasesevidently.Also,thecombiningintensitydescendswiththei
7、ncreasingofthecoatingthicknessWearmasslossofthecoatingdescends.withtheincreasingofsprayingcurrentandii河北工业大学硕士学位论文atomizingairpressureunderdryfrication.Butitascendswiththeincreasingofsprayingpotentialanddistance.Thewearmecha