《（机械工程专业毕业论文）碳纤维增强树脂基复合材料高速钻削表面质量研究.docx》由会员分享，可在线阅读，更多相关《（机械工程专业毕业论文）碳纤维增强树脂基复合材料高速钻削表面质量研究.docx（82页珍藏版）》请在第一文库网上搜索。
1、碳纤维增强树脂基复合材料高速钻削表面质量研究碳纤维增强树脂基复合材料高速钻削表面质量研究摘要碳纤维增强树脂基复合材料(CarbonFiberReinforcedComposites,CFRP)具有许多优良特性：质轻高强度、可设计性强、模量高、比强度高及耐化学腐蚀等,其在航天航空、船舶、建筑汽车等领域的应用不断扩大。与此同时，高速切削加工(HighSpeedMachining,HSM),满足了诸多领域的精密零部件高效、环保的加工要求，形成一种新趋势。由于材料结构各向异性特点、层间强度较低及碳纤维的硬度高的特点，加工容易出现分层、撕裂及刀具磨损严重等问题，使其成为典型难加工材料。本文主要采用硬质合
2、金刀具对CFRP高速钻削加工进行实验研究，研究了不同刀具几何参数和切削参数下的孔壁表面粗糙度、孔两侧分层、及轴向力，并且分别建立三者的回归方程、优化了钻削参数、归纳制孔常见缺陷及原因、深入分析了孔壁形成与分层等缺陷的产生机理。研究结果表明：刀具几何参数与切削参数对孔壁粗糙度、分层及轴向力的影响并不相同，从粗糙度来看，刀尖顶角与进给量的影响最显著、螺旋角的影响次之，主轴转速影响一般显著；从入口侧分层来看，进给量的影响高度显著，螺旋角有一定的影响；从出口侧分层来看，刀具几何参数的影响极为显著，进给量有一定影响；从轴向力而来看，进给量、刀尖顶角及螺旋角的影响极为显著。综合三方面，兼顾加工效率，高主轴
3、转速、小进给量是最优工艺参数组合；粗糙度、轴向力的经验式预测与试验真值拟合程度较高，并通过了回归方程方差检验及其系数显著性检验；基于经验模型分别获得最优钻削参数与刀具几何参数。利用体视显微镜(CCD)及扫描电镜SEM观测孔壁形貌，结合粗糙度的测量值可知，CFRP钻削孔壁表面质量随纤维角。呈周期性变化：当0二0,材料层间分离，所得表面理想；当f4或=2时，材料剪切分离，表面质量次之；当0=34时，材料受弯曲与剪切的双重作用，表面质量较差。钻削力在主切削刃正、负前角部分的分力，是两侧分层的主要原因。而钻削热对基体的软化作用及垫板的支撑作用，是出口侧的分层因子小于入口侧分层因子两个原因。由基于薄板弹
4、塑性变形理论以及能量平衡方程推导得出分层临界力的计算式，求得临界值为55.53No幅频特性显示轴向力信号主要是低频信号，主轴旋转频率信号及齿切入频率信号等，前者幅值远大于后者两者的幅值,表明高速钻削稳定性良好。关键词：CFRP,高速钻削，表面质量，分层，钻削力TheInvestigationofSurfaceQua1ityinHighSpeedDri11ingCarbonFiberReinforcedCompositesAbstractComparedwiththetraditiona1meta1materia1s,CarbonFiberReinforcedCompositeshasmanye
5、xce11entproperties,suchashighstrength-to-weightratio,highstiffness-to-weightratio,hightemperatureresistanceandgooderosionresistance.TheseoutstandingadvantagesmakeCFRPbecomemoreandmorepopu1aramongaerospace,aviation,shipbui1ding,civi1andothersfie1ds.A1thoughtheCFRP1ike1ytobethenear-net-shapedforming,t
6、omeetingtheassemb1edneed,theworkpieceneedsfurthermachining.Dri11ingprocessiswide1yusedinthemateria1machining.Atthesametime,highspeedmachininghasmeetingtheefficientandenvironmenta11yfriend1yrequirementsofprecisionpartsandcomponentsprecisioninvarietyfie1d,andbecominganewmachiningtrend.Asakindoftypica1
7、hardmachiningmateria1s,thestructura1characteristicsandspecia1physica1properties,makingtheCFRPdri11inghasriskofde1amination,surfacetearandsevere1ytoo1wareandothersseriousprob1ems.Inthisdissertation,ana1ytica1andexperimentstudiesareconductedwithcementedcarbidetoo1sinhigh-speeddri11ingCFRRBasedonthedri
8、11ingexperiment,theinf1uenceofcuttingparametersanddri11geometricparametersontheho1esurfaceroughness,de1aminationanddri11ingforcearestudied,thepredictionmode1softhemareestab1ishedbynon1inearregressionana1ysismethod,thedri11ingparametersareoptimized,thecommondri11ingdefectsandtheircausesaresummarized,
9、theho1esurfaceandde1aminationformationmechanismsarein-depthana1yzed.Itisconc1udedthattheinf1uenceofcuttingparametersandtoo1geometricparametersonho1esurfaceroughness,de1aminationandthrustforcearenotcomp1ete1yconsistent.Intermsoftheroughness,theinf1uenceofthepointang1eandfeedratearemostsignificant1y,f
10、o11owedbydri11he1ixang1e,spind1espeedtheminimum.Concerningthepee1-upde1amination,thebiggestfactorisfeedrate,thehe1ixang1ehassomeeffect,othersfactorshave1itt1einf1uence,howeverforthepush-de1amination,thedri11geometricparametersshowahigh1ysignificant,fo11owedbyfeedrate.Intermsofthethrustforce,a11offee
11、drate,thepointang1eandhe1ixang1ehavesignificanteffectonit.Takingthethreeaspectsandthemachiningefficiencyintoaccount,higherspind1espeedand1owerfeedrateistheoptimizedprocessingparameter.Theva1ueoftheroughnessandthrustforcepredictionmode1arefitgoodwiththeresu1tofexperiment,theana1ysisofvarianceandsigni
12、ficanttestofregressioncoefficientshowthattheexperientia1equationshavehighconfidence.Basedontheroughnessandthrustforcepredictionmode1,theoptima1combinationofcuttingparametersandtoo1geometricparametersareobtained.Thepicturestakenbycharge-coup1eddevice(CCD)andthescanninge1ectronmicroscope(SEM)va1idatet
13、herationa1ityofthemode1ofho1efonnation.Thesurfaceroughnessoftheho1eappearsomeregu1arity,whichisconnectedwiththefiberorientationang1e:whenequa1to0,thesurfacewhichcomefrominter1aminardissociationisbest;whenequa1to4or2,theshearedsurfaceisgood;whenequa1to34,thebendingandshearingfracturemorpho1ogymakethe
14、surfacenotsogood.Thepee1-upde1aminationiscausedbytheupwardaxia1force,howeverthepush-de1aminationresu1tfromthepushingforceofthechise1edge.Matrix-softeningbycuttingheatandthesupportprovidedbyfixmakethepush-de1aminationfactor1essthanthepee1-upde1aminationfactor.Consideringtwomode1sofdri11ing-inducedde1
15、amination,critica1thrustforceofpush-de1aminationisderived,basedone1astic-p1asticdeformationandenergy-ba1anceequation,andobtainedthecritica1thrustforce(55.53N).Accordingtothemagnitude-frequencycharacteristicsofthethrustforce,1ow-frequencysigna1isstrongerhigh-frequencysigna1,whichindicatethatthehigh-s
16、peeddri11inghasfinestabi1ity.Keywords:CFRHHighspeeddri11ing,Surfacequa1ity,De1amination,Dri11ingforce目录摘要AbstractII目录IV第一章绪论11.1 课题的来源11.2 课题的研究背景11.3 CFRP钻削研究进展31.4 课题研究的主要内容9第二章碳纤维增强树脂基复合材料的钻削试验设计102.1 试验系统102.1.1 试验材料102.1.2 实验刀具112.1.3 钻削实验加工平台122.1.4 实验质量检测设备142.1.5 加工工艺参数142.2 实验方案设计与分析方法152.2.1 高速钻削孔壁粗糙度实验152.2.2 高速钻削两侧分层撕裂试验172.2.3 高速钻削轴向力试验172.3 本章小结17第三章碳纤维增强树脂基复合材料孔壁粗糙度研究19
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