深孔加工刀具磨损的试验研究

深孔加工处于封闭或半封闭的状态下,加工过程复杂。因此,深孔加工过程中存在切削力不稳定、刀具磨损严重、刀具使用寿命低等问题。为了研究枪钻加工工艺参数对切削力和刀具磨损的影响,本文采用硬质合金枪钻作为深孔加工刀具,通过对深孔钻削的切削力和刀具磨损值的试验研究,得到了钻削工艺参数与切削力和刀具磨损之间的关系,经过分析得出了影响刀具磨损的原因。     

难加工材料枪钻加工技术研究

深孔加工是机械加工领域的重要分支,在钛合金、沉淀硬化不锈钢等难加工材料的深孔加工过程中,存在加工表面质量差、刀具崩刃、磨损严重和断屑排屑困难等问题。枪钻是深孔加工领域发展最早、应用范围最广的深孔加工刀具之一,其几何结构特殊,在深孔加工中具有加工质量好、效率高、直线度好等特点。本文介绍了枪钻的主要结构及受力情况,分析了枪钻的切削加工过程及其断屑条件,通过对切屑、切削力和切削温度的研究,得到了刀具、工艺参数以及切屑对加工质量和刀具磨损的影响规律。最后以两种典型的难加工材料为代表,分析了难加工材料深孔加工的特点。研究结果对难加工材料的枪钻深孔加工具有重要的指导意义。     

深孔加工刀具的切削力和孔圆度试验研究

深孔加工是一种封闭状态下的加工方式,加工过程中会发生很多影响加工正常进行的问题。所以,深孔加工过程中存在切削力不稳定和孔的形状精度差等问题。为了研究枪钻加工工艺参数对切削力和孔圆度的影响。本文采用硬质合金枪钻作为深孔加工刀具,通过对深孔钻削的切削力和孔圆度的试验研究,得到了钻削工艺参数和切削力、孔圆度之间的关系,经过分析得出了影响加工孔圆度的原因。这一研究对深孔加工过程中工艺参数的选择具有十分重要的作用。     

CFRP/Ti叠层材料螺旋铣孔与钻孔的刀具磨损对比与分析

针对螺旋铣孔与传统钻孔刀具磨损的问题,对CFRP/Ti叠层材料进行螺旋铣孔与传统钻孔试验。在相同加工效率及切削速度的基础上,对两种工艺加工孔的切削力及刀具后刀面磨损长度进行了测量。结果表明:制孔过程中,螺旋铣削制孔的切削力明显小于钻削制孔的切削力;加工过程中,螺旋铣削制孔的切削力比钻削制孔的切削力更加平缓;同等参数条件下,螺旋铣削加工到24孔时刀具失效,传统钻削加工到18孔时刀具失效;螺旋铣削制孔的刀具比钻削制孔的刀具更加耐磨,加工孔数更多。     

钛合金的深孔钻削技术研究

钛合金的切削加工性能差,其深孔钻削的技术难度更大。枪钻是深孔钻削的高效刀具,能有效解决钛合金的深孔加工问题。本文基于对钛合金材料切削性能和深孔钻削工艺的分析,通过深孔钻削试验,改进了钛合金叶片深孔钻削工艺,提高了枪钻寿命。     

Ti6Al4V钛合金枪钻加工轴线直线度误差试验研究

针对某大型飞机轴类零件深孔加工粗糙度差、轴线偏差和切屑不易控制等问题,进行了Ti6Al4V钛合金枪钻加工试验,测试了枪钻加工深孔的轴线偏差、孔径误差和加工表面完整性,并分析了产生偏差的主要原因。从而优化了Ti6Al4V钛合金枪钻加工工艺参数,得到了Ti6Al4V钛合金17深孔枪钻加工最佳工艺参数,最终实现了860mm深孔的枪钻加工,使得最终综合误差控制在0.2mm以内,表面粗糙度Ra小于1.6μm。     

基于枪钻的42CrMo合金钢深孔钻削分析

在深孔钻削加工42CrMo合金钢时,易造成切削温度高、刀具磨损快等问题,从而影响加工质量。针对某传动轴的深孔加工,为得到合适的切削参数、保证技术要求,利用DEFORM-3D有限元分析软件设计正交仿真试验,分析不同切削参数对切削温度和刀具磨损的影响,得到最佳的切削用量。加工结果表明,枪钻用此切削用量进行深孔加工可以满足技术要求,为优化枪钻加工42CrMo合金钢时的切削用量、提高产品质量和降低刀具磨损提供了指导。     

枪钻导流面后角对切屑性能的影响研究

枪钻加工是实现深孔加工的重要技术手段,由于孔径较大,在枪钻加工过程中,经常遇到排屑困难以及孔加工质量差等问题。而枪钻导流面作为与V型槽连接的最后一个刃磨平面,其作用往往被忽视。通过研究不同切削参数下钻削加工42CrMo合金钢材料时导流面后角对切屑、刀具磨损以及钻孔质量的影响,以被加工孔的表面粗糙度、圆度和孔径误差为指标对孔加工质量进行评价。     

枪钻角度变化对Ti6Al4V钛合金加工质量的影响研究

分析枪钻受力影响因素,对钻头受力进行简化并分析径向力、挤光转矩对深孔加工质量的影响。根据分析结果选择通过改变枪钻内、外角的方式来调整钻头受力状况。同时,考虑到枪钻外刃刃磨更加方便、对周边刀面影响较小,为降低试验干扰因素、合理选择刀具几何参数,选取枪钻外刃锋角作为单因素变量进行Ti6Al4V钛合金钻削试验,并通过分析试验结果确定外刃锋角变化对钻削质量的影响。综合考虑切削力值、切屑形貌以及加工质量等因素,给出了钻削Ti6Al4V钛合金时关于枪钻外刃锋角选择优化的建议。     

枪钻的刀具磨损及监测技术

综合国内外研究现状,介绍了枪钻的基本结构和加工系统,总结了枪钻加工过程中刀具磨损的主要形式:扩散磨损和粘结磨损,分析两种磨损形式的机理。阐述了枪钻加工过程中刀具监测技术,目前主要通过采集力、扭矩和声发射信号对刀具状态进行监测,声发射信号等可以对刀具磨损状态进行表征,提出了抑制枪钻磨损方法以及监测技术的发展趋势。     

基于Deform-3D准干式深孔BTA刀具钻削的仿真研究

采用Deform-3D有限元分析软件对准干式单刃内排屑BTA钻削做了仿真研究。应用Deform-3D软件设置模拟参数为干式钻削,在不同的切削用量情况下对切削力的大小、刀具磨损以及切削温度场进行了仿真分析,讨论了断屑判据以及分屑的形成过程,为准干式深孔加工的切削参数和刀具参数的进一步优化提供了依据。     

Cutting performance of an indexable insert drill for difficult-to-cut materials under supplied oil mist

In this study, the cutting performance of an indexable insert drill with an asymmetric geometry for cutting difficult-to-cut materials was investigated. A solid twist drill with a symmetric geometry was used to compare the cutting characteristics. The cutting characteristics were evaluated using the thrust force, inner-surface roughness of the drilled hole, wear behavior, and tool temperature. Workpieces made of stainless steel, titanium alloy, and nickel-based alloy were selected as difficult-to-cut materials, and carbon steel was also selected. The tool temperature was higher in the order of carbon steel, stainless steel, titanium alloy, and nickel-based alloy for every drill under minimum quantity lubrication cutting. The influence of the workpiece material on the thrust force was different from that of the tool temperature for the indexable insert drill, whereas that of the solid twist drill was similar to the tool temperature tendency. When cutting the titanium alloy and nickel-based alloy, the tool temperature and thrust force of the indexable insert drill were lower than those of the solid-type twist drill. The inner-surface roughness of a hole drilled with the indexable insert drill had almost the same quality as that of a hole drilled with the solid-type twist drill when cutting the difficult-to-cut materials. The wear behavior of the indexable insert drill was remarkably different from that of the solid-type twist drill, and the flaking of the coating and the abrasion wear at the rake face were notable in the indexable insert drill.     

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.     

不锈钢和钛合金工件的高效深孔钻削工艺

针对不锈钢、钛合金材料的深孔加工问题 ,分析了难加工材料的切削特性。从刀具设计及工艺方面 ,对高效深孔钻削进行了研究 ,并实际进行了切削试验 ,取得了较为满意的加工效果     

Micro-drilling of Ti–6Al–4V alloy: The effects of cooling/lubricating

This paper presents a series of experimental investigations of the effects of various machining conditions [dry, flooded, minimum quantity lubrication (MQL), and cryogenic] and cutting parameters (cutting speed and feed rate) on thrust force, torque, tool wear, burr formation, and surface roughness in micro-drilling of Ti–6Al–4V alloy. A set of uncoated carbide twist drills with a diameter of 700 μm were used for making holes in the workpiece material. Both machining conditions and cutting parameters were found to influence the thrust force and torque. The thrust force and torque are higher in cryogenic cooling. It was found that the MQL condition produced the highest engagement torque amplitude in comparison to the other coolant–lubrication conditions. The maximum average torque value was obtained in the dry drilling process. There was no substantial effect of various coolant–lubrication conditions on burr height. However, it was observed that the burr height was at a minimum level in cryogenic drilling. Increasing feed rate and decreasing spindle speed increased the entry and exit burr height. The minimum surface roughness values were obtained in the flood cooling condition. In the dry drilling process, increased cutting speed resulted in reduced hardness on the subsurface of the drilled hole. This indicates that the surface and subsurface of the drilled hole were subject to softening in the dry micro-drilling process. The softening at the subsurface of drilled holes under different cooling and lubrication conditions is much smaller compared to the dry micro-drilling process.     

TiSiC涂层钻头钻削CFRP/TC4钛合金叠层材料的研究

为解决碳纤维复合材料/钛合金叠层材料制孔刀具使用寿命短的问题,本文提出采用Ti Si C涂层来提高刀具耐用度,并研究了Ti Si C涂层钻头钻削碳纤维复合材料/钛合金叠层材料时的轴向力、刀具磨损和孔出口质量。结果表明,Ti Si C涂层刀具能减小钻削钛合金的轴向力,延长刀具寿命和改善孔出口质量,且制孔一致性良好,有利于提高钻孔质量和刀具寿命。     

钛合金TC17的高速铣削研究

在干切环境下选用了硬质合金刀具对近β相钛合金TC17进行高速铣削研究。着重讨论高速铣削过程中的铣削力、刀具磨损和刀具耐用度;研究分析各铣削参数对铣削力、刀具磨损和刀具耐用度的影响规律。     

TC4钛合金深槽插铣加工

针对钛合金深槽开槽加工效率较低的问题,对TC4钛合金深槽进行插铣开槽试验研究,并对其已加工表面形貌、切屑形态、刀具磨损及切削效率进行了分析。结果表明:插铣加工表面粗糙度较大,铣刀的端面刃为主切削刃,刀具磨损主要发生在铣刀的端面刃。对于钛合金深槽的开槽加工,插铣加工切削过程平稳,具有比层铣更高的切削效率。     

Effects of cutting parameters on tool insert wear in end milling of titanium alloy Ti6Al4V

Titanium alloy is a kind of typical hard-to-cut material due to its low thermal conductivity and high strength at elevated temperatures, this contributes to the fast tool wear in the milling of titanium alloys. The influence of cutting conditions on tool wear has been focused on the turning process, and their influence on tool wear in milling process as well as the influence of tool wear on cutting force coefficients has not been investigated comprehensively. To fully understand the tool wear behavior in milling process with inserts, the influence of cutting parameters on tool wear in the milling of titanium alloys Ti6Al4V by using indexable cutters is investigated. The tool wear rate and trends under different feed per tooth, cutting speed, axial depth of cut and radial depth of cut are analyzed. The results show that the feed rate per tooth and the radial depth of cut have a large influence on tool wear in milling Ti6Al4V with coated insert. To reduce tool wear, cutting parameters for coated inserts under experimental cutting conditions are set as: feed rate per tooth less than 0.07 mm, radial depth of cut less than 1.0 mm, and cutting speed sets between 60 and 150 m/min. Investigation on the relationship between tool wear and cutting force coefficients shows that tangential edge constant increases with tool wear and cutter edge chipping can lead to a great variety of tangential cutting force coefficient. The proposed research provides the basic data for evaluating the machinability of milling Ti6Al4V alloy with coated inserts, and the recommend cutting parameters can be immediately applied in practical production.     

钛合金深孔钻削刀具的研究

针对钛合金材料的难加工特性，选择了几种目前国内常用的硬质合金材料，并优化选择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。