碳纤维复合材料孔加工缺陷的研究进展

碳纤维复合材料属于难切削加工材料,在产品生产过程中容易出现孔的分层、出入口的毛刺和劈裂等缺陷。综述分析了碳纤维复合材料孔加工的主要缺陷和形成机理,同时给出了减少孔加工缺陷的主要途径,概括了提高碳纤维复合材料孔加工质量的有效方法,并展望了未来发展趋势。     

碳纤维复合材料数控加工研究

碳纤维复合材料是一种大量应用于航天航空领域的具有优良综合性能的难加工材料.在概要介绍其基本特性、切削机理的基础上,对用于碳纤维复合材料的切削刀具特征及切削参数作了初步研究,并给出了切削试验数据和应用实例.     

碳纤维复合材料/钛合金叠层钻孔质量研究

碳纤维复合材料(Carbon fiber reinforced plastic,CFRP)/钛合金叠层的钻孔机理不同于单层材料钻孔,钛合金切屑在排出孔外过程中会对CFRP孔质量造成损伤。为了探究CFRP在叠层钻孔时的质量特性,设计正交试验分析了钛合金切屑和切削参数对CFRP层钻孔质量的影响。观察了轴向切削力和力矩的变化以及钛合金切屑形态,分析CFRP层孔径超差和入口撕裂的机理。结果表明:大进给量条件下,高温、高硬度的钛合金切屑会对CFRP产生严重的侵蚀,是导致CFRP孔径超差的主要原因,并会增大入口撕裂程度;CFRP入口撕裂主要产生在切削速度和纤维方向夹角θ=45°的位置,低切削速度不利于切削CFRP,会加大入口撕裂程度。因此,应使用小进给量钻削钛合金层,使用大切削速度钻削CFRP层;在保证钻头强度的前提下,推荐使用具有较大容屑空间的钻头。     

碳纤维复合材料的钻削加工

文章对国内外研究碳纤维复合材料（ＣＦＲＰ）的钻削加工技术的最新成果作了概述介绍,对钻削ＣＦＲＰ材料时的分层、撕裂等孔加工缺陷进行了分类和简单分析,并指出了提高钻孔质量的关键因素和方法。     

碳纤维复合材料钻孔工艺优化

碳纤维复合材料具有比重小、刚性好、强度高、耐高温、耐摩擦、导电及耐腐蚀等优点,已发展成为继铝、钢、钛之后的第四大航空航天结构材料之一,逐渐应用于军工行业中,如喷管、发动机壳体、隔热材料、仪器舱等.同时,碳纤维复合材料具有硬度高、热导率低、层间强度低的特点,加工过程中刀具易磨损,工件散热慢,有分层、崩边等现象.根据碳纤维...     

碳纤维复合材料钻孔出口椭圆形分层缺陷的研究

碳纤维复合材料钻削孔出口附近孔壁周围材料的分层是整个孔分层缺陷的最严重部位,它主要是由于钻削轴向力引起的Ⅰ型(张开型)裂纹破坏造成的。将钻头前端未切削的工件材料部分定义为叠合层,指出叠合层的刚度分布情况是决定各个层间分层形状的关键因素。通过对叠合层刚度取向及其与分层尺寸间关系理论分析发现,以钻头轴线为中心的分层尺寸与周向角度之间存在着椭圆或近似椭圆函数关系,从而阐明了多向碳纤维复合材料孔出口椭圆形分层产生的基本原因。叠合层上刚度最大的方向也是产生最大分层缺陷的方向,叠合层主刚度方向弯曲刚度与椭圆分层长轴角间的函数关系式可以通过一系列分析和相应的力学公式推导求得,在对该函数关系式微分后即可求得椭圆形分层长轴角的数值。     

碳纤维复合材料(CFRP)钻孔出口缺陷的研究

对碳纤维复合材料(CFRP)钻孔出口的缺陷进行了试验研究,对其典型形式进行了模型总结,指出孔出口缺陷由撕裂和毛边两部分组成,其中撕裂比毛边的尺寸大。撕裂的形成过程包括两个作用阶段即横刃作用阶段和主切削刃作用阶段,其中横刃作用在撕裂形成中占主导成份。毛边缺陷通常出现在表层纤维被“顺向”切削的孔边缘部分。另外,以孔出口两侧撕裂长度平均值作为撕裂评价参数,在总结钻削试验结果的基础上探讨了钻削参数变化对撕裂大小的影响。指出随着进给速度、进给量、钻头直径和轴向力等因素的增大,撕裂缺陷将变得严重;钻头转速的增大将使撕裂值变小;将切削速度与进给速度比值控制在3000-4000以下,可以有效地减小撕裂值。     

碳复合材料钻孔加工性研究

从刀具材料,几何角度,切削用量等几个方面分析了碳复合材料钻孔工艺性和表面质量,给出了改善复合材料钻孔质量的工艺参数。     

碳纤维复合材料小孔加工难点与研究现状

碳纤维增强环氧树脂基复合材料在高新技术领域产品轻量化、小型化的发展趋势下具有广阔的应用前景和使用价值。微小零器件的连接装配需要进行大量的小孔加工,而碳纤维复合材料的难加工性以及小孔径加工时散热条件差、微小刀具刚度低等特点,使复合材料小孔加工比常规尺寸的孔加工更容易产生加工损伤,制孔形状、位置精度难以保证。列举了碳纤维复合材料常见的制孔损伤形式,分析了复合材料小孔加工的技术难点,综述了国内外在复合材料小孔加工机理、制孔刀具、制孔工艺等方面的研究现状。     

碳纤维复合材料钻削试验研究

在碳纤维复合材料切削加工过程中,经常会出现分层、劈裂等质量问题。文中为了解决碳纤维复合材料的分层问题,从而达到提高碳纤维复合材料钻削质量的目的,主要从分析碳纤维复合材料切削加工工艺特性入手,利用不同的工艺参数、加工技巧,对其进行了一系列钻削试验。通过分析试验数据,对比试验结果,从优化工艺参数、加工刀具的选用方面,提出了若干适合实际操作的工艺技巧,确定了最优的钻削方法。该方法被广泛应用到了产品中,成功改善了碳纤维复合材料的钻削质量。     

Delamination-free drilling of carbon fiber reinforced plastic with variable feed rate

A large number of drilling have been performed to assemble aircraft parts of carbon fiber reinforced plastic (CFRP). Although high quality is required in machining the holes with high productivity in terms of reliability of parts, delamination often occurs around the holes in drilling. This paper presents a novel drilling method with variable feed rate to machine the delamination-free holes at a high machining rate. In the drilling, the holes are machined at the standard feed rates when the chisel moves in material; and are finished with the negative thrust at higher feed rates after the chisel exits from the workpiece. Orthogonal cutting tests were conducted to measure the cutting forces and the friction angles for the uncut chip thicknesses and the rake angles. The negative thrusts were measured in large uncut chip thicknesses at large rake angles of the lips. Then, the drilling tests were conducted to verify the change in the cutting force in the variable feed rate drilling up to 100 holes. Negative thrust component appears consistently to raise the workpiece up in the exit process even though the tool wear progresses with repeating drillings. As a result, the variable feed rate drilling remarkably controls delamination compared to the constant feed rate drilling in the 100th drilling. The cutting process in the variable feed rate drilling is compared with the constant feed rate drilling in a cutting force model based on the minimum cutting energy. The negative thrust is verified when the friction angle becomes smaller than the effective rake angle with increasing the feed rate.     

涂层钻头钻削碳纤维复合材料的轴向力研究

不同刀具材料对碳纤维复合材料的加工有较大的影响。通过合理选择钻头的基体材料和涂层材料,基于正交试验综合分析不同涂层材料、主轴转速及进给速度对钻削轴向力的影响。试验结果表明,涂层材料对轴向力的影响最大,涂层钻头的钻削轴向力比无涂层YG6X钻头小很多,类金刚石涂层(DLC)钻头最小。TiAlN和TiCN涂层钻头都有不同程度的磨损,DLC钻头的耐磨性和加工质量都远远高于其他涂层。     

连续纤维增强玻璃钢球阀研究

介绍了由材料性能试验获取的连续玻璃纤维增强复合材料的力学性能,包括沿各个不同方向的拉伸、压缩、剪切、弯曲等性能参数,并依据这些性能参数,研究连续纤维增强玻璃钢球阀的设计要点,导出其详细设计公式。通过对材料组成及制备工艺进行改进,使得设计出的玻璃钢球阀较国内普通的玻璃钢球阀力学性能更为优秀。     

烧结金刚石套料钻钻削凯芙拉纤维增强复合材料的研究

介绍凯芙拉纤维增强聚合物基复合材料的结构和性能特点,针对复合材料在钻孔加工过程中产生各种加工缺陷的原因,采用烧结金刚石套料钻和专用的工艺装置进行加工试验,分析加工机理,给出合适的工艺参数,为加工该类纤维复合材料提供一条新的途径,具有实用和推广价值。     

Performance of plastic gear made of carbon fiber reinforced poly-ether-ether-ketone

A carbon fiber (CF) reinforced poly-ether-ether-ketone (PEEK) gear was prepared by injection molding, and its gear performance was evaluated. It was found that the wear process of the CF reinforced PEEK gear significantly varied depending on the test conditions, such as the kind of the partner gear combined and whether a lubricant exists on the engagement region or not. It was assumed that the existence of transfer film at the engagement region, the affinity between PEEK and CF, the compression modulus as well as surface hardness of the partner gear, and the characteristics of CF play a role of differentiation in the wear depth.     

Drilling of uni-directional glass fiber reinforced plastic (UD-GFRP) composite laminates

Drilling of fiber reinforced plastic (FRP) composite materials is a field open to a plethora of questions. Drilling-induced damage is a research area that has not been explored exhaustively. The present research endeavor is an effort to correlate drilling-induced damage with drilling parameters. Tool point geometry is considered a major factor that influences drilling-induced damage. Experiments were conducted and drilling-induced damage was quantified using the digital image processing technique. The results also reestablished the cutting speed to feed ratio as an important variable that influences drilling-induced damage. Mathematical models for thrust, torque, and damage are proposed that agree well with the experiments.     

碳纤维复合材料-钛合金层板钻孔质量研究

对比钻削碳纤维复合材料(CFRP),碳纤维复合材料-钛合金层板(CFRP-Ti),得出钻削CFRP-Ti时的CFRP入口分层、孔径误差、形状误差以及孔的表面粗糙度均比单独钻削CFRP时的要差.其原因是CFRP在上层,当钻削钛合金层时,一方面轴向钻削力大,钻削过程不平稳;另一方面钛合金的钻屑为螺旋长条状,这些都会影响已形成的孔壁.尤其在高转速下,此影响更为严重.     

基于非接触光声成像的碳纤维增强复合材料冲击损伤检测方法

为了探究碳纤维增强复合材料(CFRP)的损伤机制并对其制造过程进行质量监控,对 CFRP 的冲击损伤区域进行了高 分辨无损检测。 构建了全光式非接触光声显微(AONC-PAM)成像系统,利用自主开发的光学吸收结合背向散射的双对比度成 像模式,对 CFRP 在不同冲击能量下的损伤区域进行高分辨率无损检测。 实验结果显示,AONC-PAM 系统的空间分辨率为 2. 9±0. 5 μm;双对比度成像策略能以 2 s/ 帧的速率同时获得基于光学吸收和表面散射特性的图像及两者叠加的双对比度图 像;AONC-PAM 系统显示了比通用明场显微镜系统更多的成像细节,包括碳纤维分布和其他微观缺陷如纤维断裂、错位、缺束 和褶皱,可检测的微观缺陷尺寸达 10~ 20 μm,并实现了损伤区域的精准量化。     

Drilling-induced damage in uni-directional glass fiber reinforced plastic (UD-GFRP) composite laminates

Uni-directional glass fiber reinforced plastic (UD-FRP) composite materials are a feasible alternative to structural members that bear loads in only one direction. FRP composite materials have excellent properties in the direction of the fibers. Drilling- induced damage acts as an inhibitor to their application, as the holes act as stress concentration sites for failure under loading. The present study is an attempt to study the influence of drilling-induced damage on the residual tensile strength of uni-directional composite laminates and to propose a mathematical model correlating the residual strength with the drilling parameters. A finite element model (FEM) is also developed to study the drilling-induced damage in composite laminates.