共查询到19条相似文献,搜索用时 703 毫秒
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C/E复合材料螺旋铣削制孔方法抑制缺陷产生的机理 总被引:14,自引:0,他引:14
传统钻削加工碳纤维/环氧树脂(Carbon/epoxy,C/E)复合材料时容易产生加工缺陷,而螺旋铣削作为一种新的制孔方法在航空材料的加工中逐渐受到关注。为分析螺旋铣削制孔方法抑制缺陷产生的机理,以传统钻削加工为参照,分别利用螺旋铣削及传统钻削两种方法对C/E复合材料进行制孔试验,并对螺旋铣削与传统钻削刀具的运动轨迹进行分析。在具有相同的加工效率及刀具切削速度的基础上,对两种加工方法的加工参数进行优化。进行制孔对比试验,并对制孔过程中的切削温度、切削力及加工质量进行检测与分析。结果表明,切削温度是影响C/E复合材料制孔质量的重要因素,且由于螺旋铣削制孔时的切削温度显著低于传统钻削制孔温度,因此螺旋铣削制孔质量明显优于传统钻削制孔质量。螺旋铣削制孔时的切削温度较传统钻削时降低69℃以上,降幅大于36%,因此有效避免了制孔出口处的撕裂及分层现象。 相似文献
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<正>轻质高强碳纤维增强树脂基复合材料(CFRP)是运载装备减重增效的优选材料,可显著提升装备性能。此类材料构件的装配连接需加工大量连接孔,且制孔损伤容限要求苛刻。但CFRP是典型的难加工材料,钻削制孔时,与金属等匀质材料相比,材料失效行为和去除机理迥异,易在出口区域产生严重损伤,对现有加工技术提出严峻挑战,制约CFRP的应用,限制装备性能提升。本文研究CFRP的切削机理和温度影响规律,提出合理控制切削力,降低切削温度影响的方法,研发钻削刀具和工艺关键技术,实现CFRP低损伤钻削制孔。1)建立了CFRP切削加工中单侧弱约束区域材料的单纤维切削和刀具/纤维接触的理论模型,表征了钻削出口材料的切 相似文献
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玻璃纤维增强树脂基复合材料(Glass fiber reinforced plastic,GFRP)具有比强度高和比模量大等特点,广泛应用于航空航天、船舶军工和汽车制造等领域。针对GFRP复合材料制孔加工中容易出现分层、撕裂等缺陷,采用旋转超声振动套孔加工方法对其进行磨削制孔的理论和试验研究。分析了旋转超声振动套孔加工中单颗磨粒的运动学特性,基于Hashin失效准则,对GFRP复合材料最具代表性的0°和90°角度铺层玻璃纤维进行磨削常规和旋转超声振动套孔加工有限元仿真研究。相较于常规加工,超声振动加工使磨粒具有周期性动态冲击磨削效果,改变了材料的去除方式,降低了磨削力,结果表明:超声振动加工的轴向力最大降幅可达20.1%,同时有效抑制了出口分层缺陷,孔壁表面的纤维断口光滑平整,制孔质量得到有效改善。 相似文献
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《新技术新工艺》2020,(10)
复合材料因其比强度高、抗疲劳腐蚀性好、结构轻等优点广泛应用于飞机结构件中。在复合材料损伤后机械螺接修理过程中,为了解决复合材料制孔时容易出现出口分层和撕裂、表面质量不高、刀具磨损快的制孔难题,在超声纵振套磨钻切削刃的运动和制孔机理分析基础上,介绍了包括纵振手钻、套磨钻、超声电源和换能器等在内的超声纵振制孔系统,通过普通套磨制孔和超声纵振套磨制孔对比试验,研究复合材料套磨制孔过程中的排屑、刀具磨损和制孔质量问题。试验结果表明,超声纵振套磨制孔增大了排屑空间,缓解了料芯堵屑,有助于排屑;有效抑制了复合材料孔口分层和撕裂,纤维以剪切断裂为主,孔表面光洁平整,提高了制孔质量;刀具外壁磨损小,内壁磨粒锋利性保持良好,提高了刀具耐用度。 相似文献
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由碳纤维增强树脂基复合材料(CFRP)制成的圆管在钻削加工时,圆管表面与刀具相交形成相贯线形式孔边缘轮廓,随着刀具切削刃旋转至轮廓较低点过程中被切削材料的减少,切削刃外缘处从材料中切出,纤维在切削速度方向上为无未切削材料支撑的弱约束状态;随着切削刃旋转至较高点过程中被切削材料的增多,切削刃外缘处又切入材料,切削厚度的增加将带来更大的切削力,纤维与树脂基体之间更易开裂。文中对CFRP圆管钻削过程中切削刃切入、切出过程进行分析,得到其对入口、出口损伤的影响规律,通过实验分析了钻削具有不同表层铺层方向的CFRP圆管中切入、切出过程对入口、出口损伤的影响程度。结果表明,在钻削入口处曲面特征下切削刃切入、切出不同纤维铺向条件下的纤维时,产生损伤的角度范围与损伤面积均会增加,与切出过程相比,切入过程会造成更严重的毛刺、撕裂损伤。钻削出口处CFRP圆管的曲面特征对分层损伤并无显著影响。 相似文献
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为建立超声辅助螺旋磨孔过程中磨削力的预测模型,充分发挥磨削力在Ti3Al微孔磨削工艺参数优化中的指导作用,基于切屑断面面积理论,分析了超声振动下切削变形力和摩擦力的变化,建立了超声螺旋磨孔的磨削力模型。搭建超声辅助螺旋磨削Ti3Al微孔实验平台,采集磨削力数据并与所建模型进行验证。研究结果表明,磨削力随着主轴自转速度的增大而减小,并随着进给速度的增大而增大;当超声振幅由0增大至1.6μm时,平面磨削力和轴向磨削力分别减小了27.2%和28%。超声螺旋磨孔磨削力模型的预测结果与实验数据显示出良好的一致性,数值误差保持在20%以内,为超声辅助螺旋磨削Ti3Al微孔的工艺参数优化提供了理论依据。 相似文献
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Ugur Köklü Okan Demir Ahmet Avcı Ayhan Etyemez 《Journal of Mechanical Science and Technology》2017,31(10):4703-4709
Functionally graded composite (FGC) materials are categorized as advanced materials that display different thermal and mechanical responses compared with well-known composites, such as carbon fiber or glass fiber-reinforced composites. This paper presents the experimental results for the drilling of three materials, namely glass/epoxy, carbon/epoxy, and FGC material. FGC was compared with carbon and glass/epoxy composites in terms of thrust force, delamination factor, diameter of hole, and roundness during drilling. This study illustrated that the drilling performance of FGC is considerably more complicated than that of more common composite materials, such as glass/epoxy and carbon/epoxy. Delamination factor at the exit of hole during drilling of FGC was mainly affected by the material placed at the exit of the hole. The proposed cutting parameters and drill geometries to minimize the occurrence of delamination during drilling of carbon/epoxy and glass/epoxy apparently does not meet the expectation in drilling FGC. 相似文献
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研究适合快速砂型铸造用模具的表面涂层材料,该涂层材料由环氧树脂CYD-128、稀释剂660A和固化剂组成,并添加一定量的微米级Al2O3颗粒。在WTM-1E微型磨损实验机上研究该涂层的耐磨性能,并用扫描电镜和原子力显微镜分析磨损后的表面形貌。结果表明:随Al2O3颗粒含量的增加,复合涂层的摩擦因数逐渐增大,磨损率逐渐降低,当Al2O3颗粒质量分数为5%时,磨损率最低;随Al2O3颗粒含量的增加,复合涂层的磨损机制由黏着占主导逐渐转变为犁削沟占主导;采用该涂层材料处理后的快速砂型铸造用模具具有一定的耐磨性。 相似文献
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The article presents the results of tests for heat pulsing friction of brand Termar-ADF carbon frictional composite material
on the new IM-58-T2 multipurpose friction machine. The results of calculation of the temperature field, flash temperature,
and maximum temperature in model ring specimens are evaluated during bilateral friction. 相似文献
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It is difficult to machine polymer matrix composites reinforced by carbon fibre, and the holemaking process is the most necessary
machining process for composite plate products. Conventional drills have a very short life in the drilling of this kind of
composites and the quality of the hole is very poor. In this paper, the cemented or plated diamond core tools are tested to
make holes in carbon fibre/epoxy composite plates. The effects of machining parameters, cooling and chip removal on the tool
life, and the hole quality are investigated. The results indicate that the material removal mechanism of the two kinds of
diamond tools is not like the cutting effect of the conventional drilling but similar to that of grinding. Satisfactory effects
in making holes in the composites are obtained—quite acceptable machined hole quality, low costs, and long wear-resistant
endurance. 相似文献
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粉末涂料固体润滑膜滚动/滑动复合干摩擦磨损特性研究 总被引:1,自引:1,他引:1
在M-2000磨损试验机上考察了经过一次处理和经两次处理的40Cr钢环表面喷涂3种粉末涂料型固体润滑膜(P型、H型、E型)试样,在线载荷为104N/m、相对滑动速度为0.042 m/s、干摩擦滚动/滑动复合磨损条件下的摩擦磨损性能,通过扫描电子显微镜(SEM)对试样磨损表面以及磨屑进行了显微观察。结果表明:底材经过一次处理(化学底膜处理)的复合固体润滑膜试样,P型和E型在磨损后期的摩擦因数分别稳定在0.38和0.32,而H型在0.40左右跳动;P型和H型的涂层磨损脱落期为60 m in左右,E型为120 m in左右;质量磨损从小到大顺序为P型相似文献
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R. G. Guan Z. Y. Zhao Q. S. Zhang C. S. Lee C. M. Liu 《The International Journal of Advanced Manufacturing Technology》2013,67(1-4):917-923
In this paper, the effect of temperature field on microstructure of A2017 alloy during an innovative continuous semisolid rolling process with a vibrating sloping plate device was studied. The results show that the alloy temperature decreases gradually from the entrance to the exit of the roll gap. In the backward slip zone, the isothermal lines have twice buckling. In the forward slip zone, the isothermal lines have once buckling. Semisolid region moves forward from the filling mouth to the exit of the roll gap with the increment of casting temperature, and the solid fraction increases from the entrance to the exit of the roll gap. The average grain size of the product increases with the increment of casting temperature, and the plastic deformation along the rolling direction happened obviously. According to the simulation and experiment, the proper casting temperature between 650 and 680 °C is suggested. A2017 alloy strip with good surface quality was obtained. The microstructure of the product is mainly composed of fine spherical or rosette grains which were elongated along rolling direction. 相似文献
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Carlos E. H. Ventura Heitor S. Chaves Juan Carlos Campos Rubio Alexandre M. Abrão Berend Denkena Bernd Breidenstein 《The International Journal of Advanced Manufacturing Technology》2017,88(9-12):2557-2571
The aim of this work is to define the cutting conditions that allow the dry drilling of carbon fiber reinforced epoxy (CFRE) composite materials taking into consideration the quality of the drilled holes (the exit delamination factor and the cylindricity error) and the optimum combination of drilling parameters. A further aim is to use grey relational analysis to improve the quality of the drilled holes. The machining parameters were measured according to 33 full factorial parameter designs (27 experiments with independent process variables). The experiments were carried out under various cutting parameters with different spindle speeds and feed rates. Drilling tests were done using WC carbide, high-speed steel (HSS), and TiN-coated carbide drills. The experiment design was accomplished by application of the statistical analysis of variance (ANOVA). Results show that the thrust force is mainly influenced by the tool materials and the feed rate, which has a strong influence on the exit delamination factor. On the other hand, the spindle speed particularly affects the cylindricity error of the holes. Correlations were established between spindle speed/feed rate and the various machining parameters so as to optimize cutting conditions. These correlations were found by quadratic regression using response surface methodology (RSM). Finally, tests were carried out to check the concordance of experimental results. 相似文献