车削加工工业纯钛(TA2)表面粗糙度研究

对工业纯钛(TA2)进行车削加工正交切削试验,分析切削用量和表面粗糙度的关系。极差分析表明:切削用量中进给量对表面粗糙度影响最大,其次是切削速度,切削深度影响最小;表面粗糙度随着进给量的增加呈线性增大,随切削深度的增加而逐渐增大;加工TA2过程中,随着切削速度的增加,表面粗糙度值整体呈减小的趋势。由于切屑形态的变化造成切削过程不平稳,引起刀具振动,导致表面粗糙度值产生波动。     

2024铝合金超精密车削表面形貌的实验研究

超精密加工是获得超光滑高质量工件表面的重要手段,其加工条件和工艺参数对超精密加工质量有重要影响。文章设计了振幅梯度变化的T形零件进行单晶金刚石超精密端面车削,获得了不同振动条件下的加工表面形貌,振动激烈的部位形貌刀痕深度大,呈一字形重叠,粗糙度大;离中心点较近的大部分中间区域振动最小,表面呈光滑镜面;过渡区域振动平缓些,表面会出现很多类似丘陵状或鱼鳞状的多边形。探索了超精密加工进给量、主轴转速及切削深度对加工表面质量的影响。结果表明随切削进给量的增加,表面粗糙度变大;随着主轴转速增大,表面粗糙度变小,但当主轴转速增大到一定值时,表面粗糙度反而有增大的趋势;随着切削深度的增加,表面粗糙度也变大,并且从工艺参数与表面粗糙度的关系示意图可以看出,切削深度对表面粗糙度的影响要小于进给量和主轴转速对其的影响。     

基于回归分析方法的切削表面粗糙度模型预测研究

依据正交切削试验,利用回归分析方法,通过MATLAB软件建立切削参数与粗糙度之间的回归预测模型,并对回归模型和回归系数显著性进行了检验,可知该表面粗糙度预测模型是显著的,切削参数中切削速度对粗糙度的影响最显著。模型所反映的粗糙度变化趋势与切削试验结果基本一致:当切削速度和切削深度增加时,工件表面粗糙度呈逐渐上升趋势;当进给量增大时,工件表面粗糙度有所下降。     

微量润滑在GH4169高温合金车削加工中的应用

为提高GH4169高温合金的可加工性,引入了微量润滑（MQL）技术开展该材料的车削加工试验。以表面粗糙度和切削温度为性能指标,分析干切削和MQL切削条件下工艺参数对已加工表面粗糙度和切削温度的影响规律。结果表明：工件表面粗糙度值均随转速的增加而降低,随进给量的增加而增大,随背吃刀量的增加而增大;切削温度则随工件转速、进给量、背吃刀量的增加而上升;相比于干切削加工,MQL切削加工能够获得粗糙度值更小的工件表面,且切削温度更低。该研究方法对于提升GH4169高温合金产品质量和实现绿色切削具有积极的作用。     

高速铣削7050-T7451铝合金表面粗糙度研究

高速铣削广泛用于航空铝合金材料的加工,以7050-T7451铝合金材料为试验对象,运用正交试验方法分析研究了铣削该铝合金材料时,切削速度、切削深度、切削宽度和每齿进给量4个因素对表面粗糙度的影响规律,并通过多元非线性回归分析得出表面粗糙度的经验公式.研究结果表明:加工表面呈交叉织网状形貌,表面粗糙度随每齿进给量和铣削深度的增大而增大,随切削速度的增大而减小,切宽对铝合金表面粗糙度的影响不明显.铣削参数对表面粗糙度的影响显著性依次为:每齿进给量fz切削速度v轴向切削深度ap径向切削宽度ae.     

工艺参数对球墨铸铁高速平面铣削性能影响的试验研究

通过研究球墨铸铁高速平面铣削加工的工艺技术,分析了切削工艺参数对主轴功率占比、表面粗糙度及切屑形态的影响规律。结果表明:随着每齿进给量和切削深度的增加,主轴功率占比基本呈线性增大;随着切削速度的增大,主轴功率占比逐渐增大到某一值后又减小;表面粗糙度值随切削速度的增加线性减小,随每齿进给量和切削深度的增加变化不显著;随着切削速度的提高,典型切屑形态由卷曲状过渡到薄片状再到碎屑状,且切屑颜色逐渐呈现金黄色,切削深度和进给量对切屑形态的影响不明显。因此,对球墨铸铁高速平面铣削而言,在选择合理的切削深度和进给量的前提下,适当提高切削速度对主轴功率占比影响不大,却能在提高切削效率的同时,获得更好的加工质量。     

超声波振动精密切削GFRP的实验研究

为改善玻璃纤维增强塑料(Glass Fibre Reinforced Plastics)的切削加工性,提高加工精度和质量,采用超声波振动切削的方式对GFRP进行了精密切削加工.介绍了超声波振动切削的特性和GFRP的纤维束与切削速度方向的相位参数,相位参数沿圆周方向成周期性变化,变化周期为π.通过实验获得了不同切削条件下表面粗糙度的变化规律,粗糙度随相位角变化基本呈正弦规律,但在45°时粗糙度最大.振幅增大导致粗糙度明显下降.切削速度对粗糙度的变化曲线呈极值状态,在速度为100 m/min时粗糙度最小.进给量小于0.06 mm时,粗糙度呈下降趋势;大于0.06 mm时,粗糙度增加较快;而大于0.09 mm后粗糙度上升趋缓.切削深度对粗糙度的影响呈单调上升趋势.实验结果表明超声波振动切削可以使GFRP的加工表面粗糙度减少1倍,使加工质量得以提高.     

密齿硬质合金涂层刀具铣削TC4钛合金试验研究

利用单因素试验方法进行了密齿硬质合金涂层刀具铣削TC4钛合金试验,研究每齿进给量和切削速度对切削力、切削温度、加工表面粗糙度以及切屑形态的影响。结果表明:切削方向分力F_x、刀轴方向分力F_z随每齿进给量的增大而增大,进给方向分力F_y随每齿进给量的增加变化不大;切削速度小于75m/min时切削力随切削速度的增加下降较为明显;切削速度超过75m/min时切削力变化不大;切削温度受每齿进给量影响较大,且影响程度随进给量的增加而逐渐减小;随着每齿进给量f_z的增大,加工表面粗糙度值先减小后增大;在每齿进给量高于0.04mm/z时,密齿铣刀铣削TC4钛合金得到的切屑为螺卷状,且随每齿进给量的增加,切屑的曲率半径减小,随切削速度的增大,螺卷状切屑的螺距减小。     

高速铣削钛合金刀具磨损对表面粗糙度影响的研究

采用对比实验法,使用S30T硬质合金刀具对钛合金进行高速干式铣削,研究了在正常磨损阶段,主要铣削参数改变时刀具磨损对表面粗糙度的影响。结果表明:高速铣削钛合金时可得到较小的表面粗糙度值;铣削速度增加时,随刀具磨损的增大表面粗糙度值呈减小的趋势;铣削深度增大时,随刀具磨损的增大表面粗糙度值呈增大的趋势;每齿进给量增大时,随刀具磨损的增大表面粗糙度值呈先增大后趋向平稳的趋势。     

TA15钛合金切削振动与表面质量关系研究

通过单因素试验对TA15进行外圆车削加工,采集振动信号并提取信号特征值,分析了切削用量对切削振动和表面粗糙度的影响规律,揭示切削用量对振动的影响,并根据正交试验结果分析切削用量对振动和表面粗糙度影响的主次关系,得到优化的切削用量。试验研究表明:切削用量中,切深对切削振动影响最大,其次为进给量,切削速度影响最小。改变进给量时,振动加速度与表面粗糙度近似成线性正比关系;改变切深时,振动加速度随表面粗糙度的增加而增加。     

正交车铣工件表面粗糙度的试验研究

正交车铣是一种新的切削加工方法,通过试验研究了轴向进给量、周向进给量、切削深度和切削速度等参数对表面粗糙度的影响规律.结果表明,轴向和周向进给量的增大都可导致已加工件表面粗糙度值增大,切削深度和切削速度的变化对表面粗糙度的影响不显著.     

球头铣刀高速铣削淬硬Cr12模具钢的研究

通过球头铣刀高速铣削Cr12淬硬模具钢的实验,研究了切削用量对切削力和表面粗糙度的影响变化规律,并分析了产生这些变化的原因。研究结果表明：在球头铣刀高速铣削Cr12淬硬模具钢时,轴向力远远大于径向力,为主切削力;随着切削速度的增加,切削力和表面粗糙度值虽然呈现下降的趋势,但下降趋势不如普通切削时明显;切削力和表面粗糙度值随进给速度的增加而增加;当轴向切深在较小的范围内,切削力和表面粗糙度值随轴向切深增加而变化很小,只有当轴向切深超过一定值以后,切削力和表面粗糙度值才随轴向切深增加而迅速增加。     

高速铣削铝合金叶片表面质量的试验研究

使用硬质合金球头铣刀对铝合金叶轮叶片进行了高速铣削试验。研究了切削速度和进给量对加工表面粗糙度的影响。试验结果表明:在高速加工中,每齿进给量比铣削行距对加工表面质量的影响更大;提高切削速度和减少每齿进给量有利于降低加工表面粗糙度。但当切削速度超过某一范围后,进一步提高速度对降低表面粗糙度的作用并不明显;每齿进给量减小到一定范围后,表面粗糙度反而会有所增加;对于铝合金叶片曲面的加工,合理选择切削速度、进给量和行距可获得较低的表面粗糙度值和较高的加工效率。     

Surface roughness aspects in milling MDF (medium density fibreboard)

Medium density fibreboard (MDF) is an industrial wood product. It is made out of wood waste fibres glued together with resin by heat and pressure. Nowadays MDF products are preferred over solid wood in many applications due to certain comparative advantages. Milling is the machining operation frequently used in manufacturing parts of MDF. The aim of this article is to study the influence of cutting parameters (cutting speed and feed rate) on surface roughness in MDF milling. A plan of MDF milling experiments was performed with prefixed cutting parameters. The objective was to establish correlation between cutting speed and feed rate with the surface roughness in MDF panels after milling. The surface roughness decreases with an increase of spindle speed and increases with the feed rate. The milling tests showed the important role spindle speed plays on the evolution of the surface roughness as a function of material removal rate (MRR). The advantage of using a high cutting speed in MDF milling is evident.     

Experimental investigation of tool vibration and surface roughness in the precision end-milling process using the singular spectrum analysis

The vibrations on the cutting tool have a momentous influence for the surface quality of workpiece with respect to surface profile and roughness during the precision end-milling process. Singular spectrum analysis (SSA) is a new non-parametric technique of time series analysis and forecasting. The significant features of the cutting tool vibration signals from the sensors are extracted and transformed from the SSA-processed vibration signals. In the present study, SSA is applied to extract and transform the raw signals of the vibrations on the cutting tool for investigating the relationship between tool vibration and surface roughness in the precision end-milling process of hardened steel SCM440. In this experimental investigation, the spindle speed, feed rate, and cutting depth were chosen as the numerical factor; the cutting feed direction and holder type were regarded as the categorical factor. An experimental plan consisting of five-factor (three numerical plus two categorical) d-optimal design based on the response surface methodology was employed to carry out the experimental study. A micro-cutting test was conducted to visualize the effect of vibration of tooltip on the performance of surface roughness. With the experimental values up to 95% confidence interval, it is fairly well for the experimental results to present the mathematical models of the tool vibration and surface roughness. Results show that the effects of feed rate and cutting depth provide the reinforcement on the overall vibration to cause the unstable cutting process and exhibit the result of the worst machined surface. The amplitude of vibration signals along the cutting feed direction is generally larger than that along other direction. The spindle speed and tool holder type affect the stability of cutting tooltip during the cutting process.     

高速铣削过程中表面粗糙度变化规律的试验研究

在高速铣削试验的基础上 ,研究分析切削速度与进给量对加工表面粗糙度的影响。试验数据表明 ,切削速度的提高有利于改善加工表面粗糙度 ,当切削速度超过某一范围后 ,随切削速度的进一步提高 ,加工表面粗糙度的降低并不明显 ,有时还会使表面粗糙度增加。根据试验结果 ,对具体工件材料与刀具材料匹配选择合理的切削速度与进给量范围 ,可以获得最小加工表面粗糙度值     

High-performance circular sawing of AISI 1045 steel with cermet and tungsten carbide inserts

This work investigated the influence of cutting speed and feed rate on cutting forces, surface roughness, and slot width circular sawing of AISI 1045 steel. The effects of tool material (cermet and tungsten carbide) and geometry (chip breaker flute and pre-cutting/post-cutting teeth) were also investigated. Thrust and radial forces generally tended to decrease as the cutting speed increased and tended to increase with the feed rate. The lowest values of thrust and radial forces were obtained using a tungsten carbide saw ground with precutting and post-cutting teeth. With regard to the quality of the machined wall, the lowest surface roughness was obtained by applying the highest cutting speed and lowest feed rate and employing a cermet brazed saw. Under this condition, roughness values comparable to face turning and parting off operations were obtained. The cermet brazed saw was responsible for producing the narrowest slot widths.     

高速切削淬硬模具钢表面粗糙度的研究

通过正交设计方案,对淬硬到60HRC的冷作模具钢Cr12MoV进行高速车削表面粗糙度试验,分析了切削用量和刀具变量对表面粗糙度的影响规律,并建立了表面粗糙度的经验公式。表面粗糙度随着切削速度的增大而减小,随着进给量和背吃刀量的增大而增大,随着刀尖圆弧半径的增大,表面粗糙度先减小后增大。在相同条件下,陶瓷刀具加工后的工件表面粗糙度好于PCBN刀具;由表面粗糙度的经验公式可知,对表面粗糙度影响最大的因素是切削速度,其次是进给量和背吃刀量,而刀尖圆弧半径对其影响较小。     

Study on cutting force and surface micro-topography of hard turning of GCr15 steel

This work investigates the cutting force and surface micro-topography in hard turning of GCr15 bearing steel. A series of experiments on hard turning of GCr15 steel with polycrystalline cubic boron nitride (PCBN) tools are performed on a CNC machining center. Experimental measurements of cutting force, 3D surface micro-topography, and surface roughness of the workpiece are performed. The 3D surface micro-topography of the workpiece is discussed, and the formation mechanism of the 3D surface is analyzed. The influence of cutting speed and feed rate on cutting force and surface roughness are discussed. The 2D and 3D surface roughness parameters are compared and discussed. It is found that feed rate has greater influence on cutting force and surface roughness than cutting speed and there exists the most appropriate cutting speed under which the minimum surface roughness can be generated while a relatively small cutting force can be found. Recommendations on selecting cutting parameters of hard turning of GCr15 steel are also proposed.