基于改进灰狼优化算法的金刚石刀具磨损状态识别方法

传统金刚石刀具磨损状态识别方法容易受到外界干扰,导致金刚石刀具磨损状态识别效率低、误检率高,为此提出了基于改进灰狼优化算法的金刚石刀具磨损状态识别方法.利用属性权重去除金刚石刀具磨损状态数据中的冗余数据,对金刚石刀具磨损状态进行初步异常识别,将粒子群算法引入金刚石刀具磨损状态特征选择中.通过计算金刚石刀具磨损状态特征的适应度,更新了粒子速度.在引入惯性因子的基础上更新粒子位置,实现金刚石刀具磨损状态特征的选择.通过计算收敛因子找到最优位置,实现金刚石刀具磨损状态的识别.分析结果表明,基于改进灰狼优化算法的金刚石刀具磨损状态识别方法不仅在识别准确率方面具有一定优势,还可在应用过程中有效提高识别效率.     

单晶金刚石刀具切削有色金属磨损机理研究

研究单晶金刚石刀具切削有色金属的磨损机理,分析切削过程影响加工工件表面粗糙度的影响因素和切削速度、进给量、背吃刀量等因素对积屑瘤生成的影响,以及积屑瘤对刀具切削力的影响。给出了切削过程中刀具与工件接触区温度和压力过高,导致金刚石刀具刃口发生石墨化、溶解、崩刃等磨损破损。前后刀面磨损、崩刃是金刚石刀具磨损主要形态。金刚石刀具磨损是微观磨损的不断积累,其磨损程度与磨损速度取决于金刚石碳原子在有色金属或在其它非金属材料原子中的溶解率。     

金刚石切削黑色金属时刀具磨损机理的摩擦磨损试验

为了降低黑色金属金刚石切削过程中的刀具磨损,提高表面加工质量和精度,对刀具磨损机理进行了研究.通过黑色金属金刚石摩擦磨损试验,模拟了实际切削过程中的刀具磨损行为;分别采用扫描电镜(SEM) 、X射线能谱仪(EDS)以及拉曼光谱仪(RS)对工件表面形貌、实验前后工件表面化学组分变化以及金刚石磨损表面的晶体结构转变进行了检测,同时提出了用石墨化程度作为试验过程中评价金刚石磨损的指标.试验结果表明:金刚石的磨损主要与机械力和温度有关,摩擦速度和工件材料中的含碳量对其影响相对较小;石墨化磨损、扩散磨损和氧化磨损等磨损机理共存,其中石墨化为导致金刚石磨损的主要原因.结合红外热像仪测温和热传导理论推算,近似获得了摩擦界面的真实温度,且随着温度升高15％,金刚石石墨化程度显著加剧83％.作者提出,应当综合考虑热-力耦合作用下的刀具磨损机理,以便进一步探寻抑制刀具磨损的工艺措施.     

基于正交实验方法评定金刚石工具耐磨性研究

本实验研究的目的是通过对不同的加工参数对热压成型的金刚石刀具磨损量影响的分析,进而确定较理想的加工参数,实现高效率的加工。实验采用三维雕刻机铣削的工作原理,通过正交实验的设计方法,并制定不同的加工参数,刀具的磨损量应用高精密电子天平测得,刀具表面磨损形态应用体式显微镜观测。实验数据表明,对金刚石刀具磨损量影响的主要参数是切削深度,其次是进给速度,最后是主轴转速。刀具底面磨损比侧面严重,底面磨损主要以脱落为主,侧面主要以冲击破碎为主。     

金刚石刀具磨损机理的探讨

分析和探讨了金刚石刀具的磨损形态和磨损机理，提出了金刚石刀具在制造与使用时应注意的若干问题。     

金刚石薄膜涂层刀具切削性能与磨损过程的研究

金刚石薄膜具有高硬度、低摩擦系数、高耐磨性和高导热性能。金刚石薄膜涂层刀具高速干切削硅铝合金可提高生产率。通过金刚石薄膜涂层刀具的切削试验和考察其磨损过程，表明了金刚石薄膜涂层刀具的使用寿命明显高于未涂层的硬质合金刀具，金刚石薄膜涂层刀具的磨损是由薄膜的显微断裂而逐渐脱落的过程。     

聚晶金刚石刀具切削各向同性热解石墨过程中的磨损机理

针对各向同性热解石墨切削过程中刀具磨损过快的问题,采用聚晶金刚石（PCD）刀具进行了切削加工试验。研究了切削过程中PCD刀具的磨损形式、磨损规律以及刀具磨损对表面加工质量的影响。试验结果表明：PCD刀具磨损主要发生在后刀面上,磨损形式为磨粒磨损和氧化磨损。磨损区域可以分为平行沟槽和严重磨损两种形貌。初始磨损阶段,磨损带长度急剧增大,并在切削1200m后进入正常磨损阶段。切削过程中还出现了石墨切屑在磨损区域的黏附堆积和刀具崩刃现象。切削初期,随着切削距离的增大,加工表面粗糙度值急剧增大,切削距离为600m时表面粗糙度达到最大值1.7μm。     

聚晶金刚石刀具振动切削不锈钢技术研究

使用聚晶金刚石刀具进行了超声波振动切削不锈钢的实验研究,研究了切削方式对切削力及已加工表面粗糙度的影响规律。通过对刀具磨损区微观形貌的观测,分析了PCD刀具切削不锈钢时的磨损机理。结果表明,化学磨损在金刚石刀具切削黑色金属时占主导地位。超声振动切削可明显减小切削变形、切削力及刀具磨损。     

金刚石铣刀切削石材磨损实验研究

在EMCO155型数控机床上切削石材,通过改变实验参数,研究各参数对金刚石铣刀磨损量影响规律。通过设计正交实验,刀具磨损量受实验参数影响次序依次为:切削深度、进给速度、主轴转速。利用电子显微镜对金刚石铣刀磨损表面进行观察,分析金刚石铣刀磨损机理。实验结果表明:金刚石刀具磨损量随着主轴转速和切削深度的增加而增大,石材的硬度对刀具磨损影响很大。金刚石刀具的磨损主要表现为金刚石颗粒的磨平、破碎与脱落及基体表面呈现出犁沟。铣刀磨损主要以金刚石颗粒磨平和脱落为主。     

应用PCD刀具铣削砂型的刀具磨损机理和预测模型

针对无模铸造成形技术在铸型制作中的优势,基于聚晶金刚石(Polycrystalline diamond,PCD)刀具铣削砂型试验,研究了PCD刀具铣削砂型的磨损机理,构建了刀具磨损率的预测模型。使用扫描电镜观察了PCD刀具刀面磨损带的微观形貌,研究了刀具磨损随加工时间的变化规律和磨损机理。结果表明:在砂型加工过程中,凸起的砂粒对刀具表面的高频刻划和冲击导致刀具表面金刚石颗粒解理断裂和金刚石颗粒间黏结材料被刮除,从而造成金刚石颗粒脱落;刀具中的微观缺陷和砂型中的"硬点"造成刀具微崩刃。基于支持向量机(Support vector machines,SVM)回归分析算法,应用Matlab软件编译了PCD刀具相对加工量的磨损率回归程序,以正交试验结果为训练样本,构建了刀具磨损率预测模型。应用该模型预测了工艺参数对刀具磨损率的影响,为砂型高效加工的刀具磨损控制提供了依据。     

Tool wear and its effect on surface roughness in diamond cutting of glass soda-lime

For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. Many researches on diamond tool wear in glass cutting rest on wear phenomenon describing simply without analyzing the genesis of wear phenomenon and interpreting the formation process of tool wear in mechanics. For in depth understanding of the tool wear and its effect on surface roughness in diamond cutting of glass, experiments of diamond turning with cutting distance increasing gradually are carried out on soda-lime glass. The wear morphology of rake face and flank face, the corresponding surface features of workpiece and the surface roughness, and the material compositions of flank wear area are detected. Experimental results indicate that the flank wear is predominant in diamond cutting glass and the flank wear land is characterized by micro-grooves, some smooth crater on the rake face is also seen. The surface roughness begins to increase rapidly, when the cutting mode changes from ductile to brittle for the aggravation of tool wear with the cutting distance over 150 m. The main mechanisms of inducing tool wear in diamond cutting of glass are diffusion, mechanical friction, thermo-chemical action and abrasive wear. The proposed research makes analysis and research from wear mechanism on the tool wear and its effect on surface roughness in diamond cutting of glass, and provides theoretical basis for minimizing the tool wear in diamond cutting brittle materials, such as optical glass.     

Study on tool wear characteristics in diamond turning of reaction-bonded silicon carbide

Tool wear is one of the most critical problems in machining hard, brittle materials. In the present work, diamond turning experiments were performed on reaction-bonded silicon carbide, and the tool wear characteristics were investigated. A special kind of wear pattern, namely periodical groove wear, was identified on the flank face of the tool, where the periodicity of the microgrooves was the same as the tool feed. Geometrical analysis showed that the periodical groove wear was caused by the tool feed marks on the machined surface. Laser micro-Raman spectroscopy indicated that the high-pressure abrasive wear at the tool?Cworkpiece interface dominates the wear behavior, rather than the diamond?Cgraphite transformation. By swinging the tool around its curvature center during the cutting process, the periodical groove wear pattern was suppressed, and the tool wear was reduced significantly.     

金属结合剂砂轮精密成形磨削T15工具钢零件的实验研究

采用金属结合剂金刚石砂轮对T15工具钢进行成形磨削加工实验,获得了形面精度保持性好的成形磨削砂轮,并用其进行长时间磨削加工,得到了满足形面加工精度要求的加工试件.实验表明,采用电火花修形方法对金属结合剂砂轮进行精密修形,可获得满足成形磨削加工要求的砂轮轮廓;在成形磨削过程中,凹槽侧面磨损率始终最大,而砂轮回转面的磨损最为稳定.     

Investigation of tool wear suppression in ultraprecision diamond machining of die steel

Rapid tool wear in diamond machining of steel can cause catastrophic failures. Despite several approaches to reducing tool wear, diamond machining of steel for industrial applications remains limited. We investigated two solutions, namely plasma nitriding treatment for workpiece surface modification and elliptical vibration cutting for cutting process modification, to determine their effect on reducing tool wear in diamond machining of AISI 4140 die steel. Furthermore, a new approach by combining the two solutions was also explored. Experimental results showed that diamond tool wear could be reduced by several orders of magnitude and mirror-quality surface can be obtained by using either the plasma nitriding treatment or the elliptical vibration cutting. However, in contrast to our expectations, combining the two solutions did not yield further improvement of either the surface finish or the reduction of tool wear compared with that of elliptical vibration cutting alone due to microchipping. Care has been taken to investigate the mechanism responsible for microchipping, and it was found that microchipping is highly dependent on the crystal orientation of the diamond. A diamond tool with the (1 1 0) plane as the rake face and the (1 0 0) plane as the flank face was more resistant to damage, and the microchipping induced in the combined cutting process was almost completely suppressed.     

车削加工陶瓷材料时刀具磨损表面形态的研究

分别使用硬质合金刀具、金刚石刀具、立方氮化硼刀具对氟金云母陶瓷及二硅酸锂玻璃陶瓷材料进行车削试验。利用显微镜观察刀具磨损形貌,通过能谱分析研究了刀具的磨损机理。试验结果表明,刀具磨损部位主要集中在刀尖和后刀面,刀具磨损形式主要为磨料磨损和粘结磨损。用硬质合金刀具车削氟金云母陶瓷时,切削深度越小,磨料磨损越严重。     

纯钒车削刀具磨损表面形态及机理研究

对金刚石刀具、涂层刀具及硬质合金刀具车削纯钒时刀具磨损形态及其磨损机理进行观察和分析.结果表明,在所选取条件下,不同刀具材料对工件材料切削时表现出的刀具磨损形态主要为前刀面磨损、后刀面磨损、微崩刃、剥落和粘结等.刀具的前刀面主要是沿切屑流出方向的沟槽形月牙洼磨损,而后刀面以粘结磨损为主.CD10刀具和H10非涂层刀具具有较佳的切削性能,而H13A非涂层刀具和GC1025涂层刀具不适于纯钒车削.     

3D characterisation of tool wear whilst diamond turning silicon

Nanometrically smooth infrared silicon optics can be manufactured by the diamond turning process. Due to its relatively low density, silicon is an ideal optical material for weight sensitive infrared (IR) applications. However, rapid diamond tool edge degradation and the effect on the achieved surface have prevented significant exploitation. With the aim of developing a process model to optimise the diamond turning of silicon optics, a series of experimental trials were devised using two ultra-precision diamond turning machines. Single crystal silicon specimens (1 1 1) were repeatedly machined using diamond tools of the same specification until the onset of surface brittle fracture. Two cutting fluids were tested. The cutting forces were monitored and the wear morphology of the tool edge was studied by scanning electron microscopy (SEM).The most significant result showed the performance of one particular tool was consistently superior when compared with other diamond tools of the same specification. This remarkable tool performance resulted in doubling the cutting distance exhibited by the other diamond tools. Another significant result was associated with coolant type. In all cases, tool life was prolonged by as much as 300% by using a specific fluid type.Further testing led to the development of a novel method for assessing the progression of diamond tool wear. In this technique, the diamond tools gradual recession profile is measured by performing a series of plunging cuts. Tool shape changes used in conjunction with flank wear SEM measurements enable the calculation of the volumetric tool wear rate.     

Ultraprecision turning of electroless nickel: effects of crystal orientation and origin of diamond tools

This paper deals with (i) the performance of natural and artificial diamond tools and (ii) the effects of crystal orientations at rake face of diamond tool for long distance (>200 km) ultraprecision machining of electroless nickel. The criteria for cutting performance of the diamond tool include flank wear, crater wear, workpiece surface finish, and cutting forces. Experimental results show that the natural diamond tool has superior performance compared to the artificial one as it experienced lower cutting forces and lower flank and crater wears. It was also found that the cutting tool with {110} crystal orientation at rake face performs better than the tool with {100} crystal orientation in terms of amount of wear, surface finish, and cutting forces.     

黑色金属的超低温金刚石超精密切削

黑色金属的超精密切削问题一直是超精加工领域中未能解决的难题。本文提出了在超低温状态下用天然金刚石单晶车刀超精密切削黑色金属的新工艺,为解决这个难题开辟了新的途径。实验结果表明,在超低温状态下,金刚石车刀切钢时的急剧磨损可以有效地被抑制,刀具寿命增加,从而使黑色金属的金刚石超精密切削成为可能。