钻削飞机钛合金结构维修孔的钻头横刃优选试验

针对飞机钛合金薄壁结构维修工艺孔的手工钻削特点,选取了三种不同横刃形状的麻花钻头,通过所构建的微量复合油雾喷射润滑(CMJ)条件下的钻削试验系统,开展了钻头横刃形状对钻削性能影响的对比试验,优选出适合战伤抢修环境下使用的飞机钛合金蒙皮钻削的钻头形状,以期提高飞机钛合金结构的修理质量和效率。试验表明,横刃形状为S型钻头最适合飞机钛合金薄壁结构维修工艺孔钻削,虽然S型和短横刃型的钻头均可有效降低钻削轴向力,提高孔口圆度,但短横刃钻头因横刃区域面积小,磨损较为严重。     

基于DEFORM-3D的钛合金钻削温度场研究

为研究麻花钻的钻削参数对钛合金钻削温度的影响规律,采用DEFORM-3D软件对钛合金的钻削加工进行有限元仿真分析,建立钻削温度场模型,应用正交试验设计分析钻头直径、钻削速度和进给量三个钻削参数对钻削温度场的分布及温度的影响。通过极差分析,以图表直观反映各因素对钻削温度的影响程度,并获得最优钻削参数组合。仿真结果表明:钻削速度对于钻削温度的影响最为明显,进给量次之,钻头直径影响最小。     

钛合金材料深孔钻削工艺研究

钛合金的切削加工性能差，尤其是钻削深孔的技术难度更大。这里通过对钛合金材料的切削性能和深孔钻削工艺的研究，设计出了一种专门用于钻削钛合金的深孔钻头，并通过一系列钻削试验表明，其工艺效果良好，有效地解决了钛合金材料的深孔钻削。     

钻头几何参数对低频振动钻削CFRP/钛合金叠层材料钻削轴向力及温度的影响

通过开展低频振动钻削叠层材料单因素试验,研究了刀具的顶角、螺旋角和后角对钻削轴向力及温度的影响。结果表明:钻头顶角越大,轴向力越大,螺旋角的变化对钻削CFRP层轴向力影响较小;在钻削钛合金层时,轴向力随着螺旋角的增大呈先下降后上升的趋势,钻头后角越小,轴向力越大;钻头几何参数对钻削温度的影响可以忽略,得出较为适合CFRP/钛合金叠层材料振动制孔的钻头几何参数为顶角120°、螺旋角25°、后角20°。     

整硬麻花钻横刃轴向前角对TC4钛合金钻削性能的影响研究

TC4钛合金在钻削加工过程中存在切削力大、切削温度高、刀具磨损严重以及寿命短等问题,属于典型的难加工材料。采用三款不同横刃轴向前角的整体硬质合金麻花钻对TC4钛合金进行钻削实验,分析不同轴向前角对切削力、切屑形态、刀具磨损与寿命的影响。结果表明：正轴向前角的钻头切削更锋利,切削阻力小;正轴向前角钻头的寿命高于0°轴向前角和负轴向前角钻头。在TC4钛合金的钻削加工中,横刃轴向前角取正值可以提升刀具寿命。     

阶梯钻头钻削CFRP/TC4钛合金叠层材料研究

针对CFRP/钛合金叠层材料传统钻削加工过程存在钻削轴向力过大、切削温度高、刀具磨损严重的问题,采用新型阶梯麻花钻对CFRP/钛合金叠层材料进行钻削试验,研究了新型阶梯麻花钻钻头在CFRP/钛合金叠层材料制孔时的轴向力、切削温度和刀具磨损。试验结果表明,阶梯麻花钻刀具能够有效降低钻削的轴向力、降低多孔钻削温度,提高刀具耐用度,具有良好的CFRP/钛合金叠层材料制孔性能。     

钛合金TC4的钻削力试验研究

钛合金TCA属于较难加工材料,其小孔钻削尤为困难。为得到钻头直径、钻削参数（进给量、切削速度）和刀具材料对钻削力的影响规律,采用标准高速钢钻头对TCA与45钢进行了钻削对比试验,并用多元线性回归分析模型分别建立了扭矩和轴向力的经验公式。结果表明,TC4的钻削力比45钢大,钻削参数对钻削力的影响规律与45钢基本相同,即钻头直径对扭矩和轴向力影响最大,进给量次之,切削速度的影响最小。     

麻花钻钻尖几何参数对Ti6Al4V钛合金钻削性能的影响

采用单因素试验法,利用Third Wave AdvantEdge有限元软件研究麻花钻的钻尖几何参数对钛合金钻削工艺性的影响,运用Power Law本构模型建立Ti6Al4V钛合金材料参数。验证麻花钻参数在合理的取值范围内,Carbide-General硬质合金麻花钻不同的后角、螺旋升角、横刃斜角和刃口钝圆半径对钛合金钻削性能的影响。通过钛合金钻削过程的有限元分析,为麻花钻钻削钛合金材料时的钻头几何参数合理选择提供了参考依据。     

钛合金钻铰削孔加工试验

钛合金钻削加工时,容屑空间为半封闭型,尤其在加工深孔时,切屑容易堆积阻塞在钻槽中,妨碍切削液流至钻头切削部分,使钻削过程中产生的热量散发不出去,加上钛合金材料导热性差,易造成切屑过分堆积或黏在刀尖上,出现烧刀现象,导致钻削加工困难,为此,开展钛合金钻铰削孔加工试验.     

钛合金钻削

钻削时钻头的容屑空间为半封闭型,希望切屑成碎块排屑。螺旋卷切屑特别是在钻深孔时,容易堆积阻塞在钻槽中影响切屑排出,并且会妨碍切削液流至钻头的切削部分,结果使产生的热量过多,钻头提早磨损变钝。钛及钛合金钻削时生成长而薄的卷曲切屑,再加上钻削产生热量多和材料的导热性差,容易造成切     

钛合金钻削加工及其新发展

从钛合金自身的切削加工性能出发,系统介绍了钛合金的切削加工基本原则。阐述了传统钛合金在钻削加工中常出现的几点问题:钻头材料、钻头几何参数分析和冷却介质的选择。根据钛合金的导热率低、弹性模量低、硬度较低和化学活性强等特点合理地调整钻头材料的选择,对原有钻头几何参数进行优化,正确选取冷却介质。并介绍了当前钛合金切削加工技术的新发展。     

Ti6Al4V钛合金枪钻加工的切削力试验研究

钛合金在深孔加工过程中存在刀具磨损严重和加工表面质量差等问题。本文采用整体硬质合金单刃枪钻作为深孔加工刀具,通过对刀具结构的分析和对Ti6Al4V钛合金深孔钻削的切削力试验研究,得到工艺参数对切削力的影响规律,结合制孔的表面粗糙度,优化了钛合金枪钻加工工艺参数。同时,通过刀具的磨损分析得到了钛合金枪钻加工过程中刀具的主要磨损形式。     

Drilling models for a synthetic cutting fluid

The primary objective of this research was to develop relationships which predict tool wear from measured cutting forces. Different cutting speeds and feed rates were examined. The workpiece materials used were a medium-carbon steel and a titanium alloy. A synthetic cutting fluid was used with a 9.525 mm drill and a 6.350 mm drill, for drilling the medium-carbon steel and the titanium alloy, respectively. Preliminary testing was conducted to find the optimal values for cutting speeds and feed rates. The main drilling tests were performed using the cutting conditions resulting from the preliminary tests. Statistical analysis of the results of the main drilling tests showed that the axial force was significant at the 5 per cent level in models for both materials. It also showed that the moment about the vertical axis was significant at the 5 percent and the 15 per cent levels in the models for the titanium alloy and the medium-carbon steel, respectively. The model for the smaller holes drilled into the more homogeneous material, the titanium alloy, was more accurate in predicting tool wear.     

Optimization of cutting parameters on drill bit temperature in drilling by Taguchi method

In this study, the optimization of the cutting parameters on drill bit temperature in drilling was performed. Al 7075 work piece and the uncoated and Firex® coated carbide drills in the experimental were used. The optimization of the cutting parameters was evaluated by Taguchi method. The control factors were considered as the cutting speed, feed rate and cutting tool. Taguchi method was used to determining the settings of cutting parameters. The L₁₈ orthogonal array was used in experimental planning. The most significant control factors affected on drill bit temperature measurements was obtained by using analysis of variance (ANOVA). Taguchi design method exhibit a good performance in the optimization of cutting parameters on drill bit temperature measurements. In addition, the empirical equations of drill bit temperatures were derived by using regression analysis. The obtained equations results compared with the drill bit temperature measurement results. The empirical equations results indicated a good agreement with experimental results.     

CFRP与钛合金叠层制孔钻头横刃结构优化

针对碳纤维复合材料(CFRP)与钛合金夹层结构制孔过程中加工质量、制孔效率与钻头寿命低等问题,以钻头的横刃结构为主要研究对象设计试验方案,对钻头横刃结构进行优化,以提高加工质量、制孔效率与钻头寿命。结果表明:优化后的横刃结构加工性能优于普通"X"形钻头横刃结构,不论是碳纤维复合材料部位还是钛合金部位轴向切削力明显减小。     

钛合金深孔钻削钻头刀片材料和几何参数的选择

这里以难加工材料钛合金为研究对象，针对钛合金材料的加工难点特性，选择目前国内相应的硬质合金材料，并优化组合出不同的钻头几何参数，进行了深孔钻削试验。通过对试验结果进行分析，确定出适合加工钛合金材料的深孔钻用刀片材料和几何参数。     

陶瓷复合构件的钻削力试验研究

以典型的陶瓷复合构件(陶瓷/玻璃钢/铝合金)为例,通过烧结金刚石套料钻头定压加工试验,深入分析了孔加工过程中的钻削力变化规律。通过正交试验和多元回归分析,建立了综合考虑钻头参数和切削用量的工程陶瓷套孔加工钻削轴向力的经验公式,并分析了各参数对钻削轴向力的影响。研究成果为工程陶瓷及陶瓷复合构件套孔加工时钻头参数和切削用量的优化选择提供了参考依据,对专用机床的开发也具有一定的指导意义。     

Effects of different cooling conditions on twist drill temperature

In the past, many researchers have studied wear developed on drilling tools mainly due to the high temperatures generated which accelerate thermally related wear mechanisms and thereby reducing tool life. This paper deals with an experimental investigation on the effect of an internal coolant approach (for different air pressure) on drill bit temperature, comparing it with an external coolant approach and dry cutting. Drill temperatures were measured by inserting standard thermocouples through the coolant (oil) hole of TiN/TiAlN-coated carbide drills. Experimental studies have been conducted using Al 2014 alloy materials. In the drilling tests, cutting conditions had different spindle speeds, coolant approaches and feed rate values. The settings of drilling parameters were determined by using the Taguchi experimental design method. An orthogonal array, the signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) were employed to analyse the effect of coolant approaches and drilling parameters. The objective was to establish a model using multiple regression analysis between spindle speed, coolant (air) pressure and feed rate with the drill bit temperature. Mathematical models for drill bit temperature are proposed that agree well with the experiments.     

铝合金加工用变导程钻头切削试验

通过合理选择刀具几何参数,针对麻花钻螺旋角及导程的研究,设计一种适合加工铝合金的变导程钻头。通过与普通(恒导程)麻花钻的对比切削试验,得出结论:在切削铝合金材料时,变导程钻头的切削性能优于普通恒导程钻头。其切屑形态较好,切削力小,不易粘刀,排屑顺利,被加工孔表面质量好。