金刚石锯片节块表面金刚石分布与单颗金刚石切削厚度的计算

通过分析金刚石圆锯片节块工作面上金刚石的分布状态和锯片工作时的运动特点 ,求出了节块工作面上出刃金刚石之间的距离和金刚石的运动轨迹 ,据此推导出单颗金刚石切削厚度的计算公式 ,并讨论了切削厚度与锯切参数和节块结构之间的关系     

大切深锯切石材中锯片受力的有限元分析

通过测量大切深锯切石材条件下锯片承受的垂直力、水平力以及主轴消耗的净功率,分析了锯切力在锯切弧区内合力作用点的位置,确定了锯切弧区内载荷的分布情况.在此基础上,利用有限元方法对某一典型锯切参数下锯片基体和锯切弧区内锯齿端面的应力分布情况进行了计算分析.采用屈曲分析研究了使锯片丧失稳定性的临界载荷及其影响因素.研究表明,锯切弧区内锯切载荷基本上按三角形规律分布.锯切弧区内金刚石节块表面前后端应力存在梯度,而且随着节块长度的增大而增大.锯片的临界载荷随着锯片厚度、转速和夹紧比的增大而增大,随着锯片直径的增大而减小.     

高效锯切石材时金刚石形貌状态形成机理及控制技术研究

探讨锯切石材过程中节块中金刚石空间分布对其形貌状态形成机理的影响。在此基础上,构造节块表面最佳金刚石形貌状态比例。分析高效锯切条件下节块的磨损特点和形成最佳表面状态的条件。在综合考虑锯切参数组合、金刚石强度、晶形分布特点以及镀膜金刚石的使用效果的基础上,提出在高效条件下有效控制节块处于最佳表面状态,从而实现低成本高效锯切石材的技术。     

径向超声锯切系统的实现及其应用探索

超声加工为硬脆性材料零件制造提供了一种高效精密加工方式,随着对超声加工研究的不断深入,超声辅助加工的形式也越来越多,提出一种结合径向超声振动辅助超薄金刚石锯片进行光学玻璃材料锯切研究。利用Pro/E建模与有限元分析手段,对采用二级变幅杆来实现超声振动方向的轴-径向转变进行了设计和仿真,完成了径向超声振动锯切装置的设计制造,并利用该装置,进行了光学玻璃的锯切试验,探索径向超声振动中单颗磨粒最大切削厚度对锯切过程机理的影响,试验结果表明在超声锯切过程中,单颗磨粒最大切削厚度对锯切比能的影响并不显著,而传统锯切方式中锯切比能随之增大而减小,这与光学玻璃材料在锯切过程中的材料去除方式有着一定关系,超声锯切过程中材料更多以脆性断裂方式去除,同时,超声振动在锯切过程中减少了金刚石锯片与工件间的摩擦,从而降低其能耗。     

钎焊金刚石锯片加工HRB400钢的模型及试验分析

尝试以HRB400螺纹钢的切屑厚度为切入点,对单层钎焊金刚石锯片锯切性能进行研究。建立锯片切割螺纹钢理论模型,通过计算得单颗金刚石最大锯切厚度值。通过试验得到的切屑类型有剪切屑及少量熔球屑,对剪切屑厚度值进行测量并与切屑厚度理论计算值进行比较,发现两者之间的数值吻合很好。经过分析得到螺纹钢锯切加工模型,探讨金钢石锯片加工钢铁材料时的锯切机理。     

实现花岗石高效锯切的关键因素分析

分析了锯切花岗石过程中金刚石节块磨损机理。探讨了不同品质金刚石的失效特点及其对结合剂的要求,指出在同一节块中使用混合品质金刚石是造成金刚石非正常失效的直接原因。在分析了锯切中节块表面载荷分布特征的基础上,提出沿节块表面不同载荷区域使用不同品质金刚石和相应结合剂系统。试验结果表明,在节块成本和节块耐磨度不变的前提下,金刚石非正常失效率大大下降,锯切效率提高了60%。     

电镀金刚石线表面磨粒密度对锯切性能影响分析

电镀金刚石线广泛应用于光伏太阳能和半导体行业的硅晶体切片加工,其表面的磨粒密度对锯切性能有很大影响。为了评价表面不同磨粒密度的电镀金刚石线的锯切性能,以光伏多晶硅为试件开展了锯切试验,分析了表面形貌、表面粗糙度和锯切效率的影响规律。研究结果表明:采用表面磨粒密度为210～230个/mm与290～330个/mm的两种金刚石线锯切的表面塑性沟槽所占比例较大,没有明显的较大尺寸脆性微凹坑。表面磨粒密度为210～230个/mm的金刚石线切割形成的硅片表面粗糙度最低,金刚石线表面过低或过大的磨粒密度会使硅片表面粗糙度变大。金刚石线的切割能力和锯切效率随着表面磨粒密度的增大而有所提高。综合考虑切片表面形貌和粗糙度等方面的质量要求与金刚石线的锯切能力和制造成本,建议金刚石线表面磨粒密度在210～330个/mm较为适宜。     

锯切条件对金刚石节块磨损的影响

在圆盘锯机上，用金刚石单刀块锯切花岗石，测量金刚石节块在不同加工工艺参数和不同冷却液条件下的磨损显，并观察节块的磨损状况。在实验的基础上，探讨锯切条件对金刚石节块磨损的影响原因。结果表明，金刚石节块的磨损量随着锯切工艺参数的改变而改变；与水冷却相比，采用GD型润滑冷却液冷却能有效地降低节块的磨损量。     

锯切条件对金刚石节块磨损的影响

在圆盘锯机上，用金刚石单刀块锯切花岗石，测量金刚石节块在不同加工工艺参数和不同冷却液条件下的磨损量，并观察节块的磨损状况。在实验的基础上，探讨锯切条件对金刚石节块磨损的影响原因。结果表明，金刚石节块的磨损量随着锯切工艺参数的改变而改变；与水冷相比，采用ＧＤ型润滑冷却液冷却能有效地降低节块的磨损量。     

不同结合剂金刚石锯片精密锯切石英玻璃研究

探讨石英玻璃的精密锯切,通过两种不同结合剂的金刚石薄锯片对石英玻璃进行精密锯切,测量和分析锯切过程中的锯切力,并结合锯切力比、比能来研究不同结合剂金刚石锯片对石英玻璃的锯切特征。结果表明:随着切深和进给速度增大,锯切力增大;随着锯片转速增大,锯切力减小,力比在2.11~2.46之间,接近于金刚石砂轮磨削硬质合金的力比,比能在4"10J/mm3之间,树脂锯片锯切石英玻璃的锯切力和锯切比能较金属锯片小,而锯切力比较金属锯片大。     

Friction studies on the process in circular sawing of granites

An investigation is reported of the friction characteristics of the process in circular sawing of granites with diamond segmented sawblade. The sawing forces were measured and specific sawing energies were calculated in sawing five types of typical granite at specific removal rates ranging from 25 to 200 mm²/s. Coupled with SEM observations of the sawn granite surfaces, a quantitative analysis for sawing energy suggests that most of the sawing energy should be expended by friction of sliding between diamonds and granites. The effect of sliding friction was discussed by introducing a new quantity which is called mean chip longitudinal area. This revised version was published online in August 2006 with corrections to the Cover Date.     

道路混凝土用圆锯片的干锯切技术

针对道路混凝土的主要性能特点,介绍并讨论了道路混凝土干锯切的若干技术,最后总结提出可最大程度提高锯切道路混凝土效率和提高锯片寿命的锯片设计制造原则。     

Sawing performance comparison of brazed and sintered diamond wires

Great attention has been paid on fabricating diamond wire by using the brazing diamond because of its strong chemical bonding strength and controllability of grits distribution. Although several serving performances of brazed diamond wire have been reported, seldom do these studies refer to its process characteristics. Sawing performances of a brazed diamond wire are investigated and compared with those of a sintered diamond wire on a wire saw machine. The surface topographies of beads selected from the two wires are micro observed before sawing. The sawing tests are carried out in constant feed rate feeding(CFF) and constant normal force feeding(CNFF). In CFF test, sawing force, power, and the cut depths of positions on contact curve are measured. Then, coupled with the observations of beads topographies, sawing force and its ratio, relations of power against material removal rate, and contact curve linearity are compared and discussed. In CNFF test, the sawing rates of the two wires are investigated. The results indicate that the brazed wire performs with lower sawing force(less 16% of tangential force and 28% of normal force), more energy efficiency(nearly one-fifth of sawing power is saved), at a higher sawing rate (the rate is doubled) and with better contact curve linearity as compared with the sintered wire. This proposed research experimentally evaluates the sawing performances of brazed diamond wire from the aspect of process parameters, which can provide a basis for popularizing the brazed diamond wire.     

Study on the thermal wear of diamond segmented tools in circular sawing of granites

An investigation is reported of an analysis on the thermally induced sawblade wear in circular sawing of granites with diamond segmented tools. The temperatures at the diamond–workpiece interface were measured in dry sawing using a foil thermocouple in order to examine the contribution of temperatures to the wear of the segments. Scanning electron microscope and energy dispersive spectrometers were employed to analyze the mechanisms for the bonding of Ti/Cr-coated diamonds to an iron-based matrix. Over 90% of the consumed energy was found to conduct into the diamond segments as heat in the sawing. Strong metallurgical bonding was observed at the diamond–matrix interface and subsequently the retention ability of the matrix to diamonds was increased. However, the retention effect of the coating was greatly offset by the disparity of diamond crystal strength, which could be improved by multistage shape selecting and magnetic separating. Coupled with the mechanisms for thermal wear, attempts were made to reduce thermally induced wear by using Ti/Cr-coated diamonds, reducing the disparity of diamond crystal strength, designing unique structured segments and selecting optimal machining parameters.     

锯切用量对花岗石可锯切性影响的试验研究

得到用金刚石锯片锯切几种典型花岗石过程中锯片耐磨度与切削用量的对应关系曲线。从锯切后花岗石表面的ＳＥＭ照片所揭示的花岗石破坏机理，对该曲线进行解释分析。对现仍比较花岗石加工性好坏的实验方法提修改建议。     

三刃结构金刚石锯片的设计及切割特点

研制了三刃结构的金刚石圆锯片,其切割特点是锋利、耐磨、平稳。刀头沟槽深度为１．０～１．２ｍｍ,金刚石浓度４４％～４８％,采用复合基胎体。调整锯片进给速度和切深可获得高的切割效率和使用寿命。该锯片可使花岗岩的切割效率提高４０％～５０％,综合效益提高２０％～３０％。     

Experimental investigation on cutting mechanisms in fixed diamond wire sawing of bone

Bone sawing has been widely used in performing bone surgery. However, thermal necrosis, loss of cutting precision and surface damage may occur in cutting process. The primary objective of this research is to improve cutting performance of bone by advantages of diamond wire sawing. Mechanism of material removal, cutting force, temperature and surface quality are analyzed based on experimental results. It is indicated that wire sawing provides small depth of cut, which is effective to obtain ductile material removal mode. Due to small material removal rate per abrasive, thermal energy is low and most of the heat can be taken away by the cyclic wire and bone chips. Consequently, cutting force and temperature in cutting zone are lower than that of traditional sawing. Due to the high efficiency of chip ejection, burrs and fracture are reduced and a significant improvement in surface quality is achieved. Based on cutting experiments with various values of cutting parameters, it is observed that better performance is achievable at higher wire speeds. These results provide a valuable basis for application of wire sawing and understanding of bone cutting mechanisms.     

锯切花岗石过程中金刚石串珠的磨损特性

通过跟踪烧结式金刚石绳锯切割花岗石过程中串珠直径磨损及串珠表面金刚石磨粒的磨损,研究串珠的磨损规律,并建立金刚石串珠的磨损模型。进行金刚石绳锯切割花岗石试验,试验结果表明,在金刚石串珠锯切过程中,单颗串珠沿其轴向出现不均匀磨损。串珠前端的磨损量会明显大于串珠中、后端磨损量,串珠后端的磨损也略大于串珠中端的磨损,串珠呈现腰鼓状磨损;串珠前端金刚石磨粒的平均出露高度高于串珠中、后端的磨粒平均出露高度,但在岩屑的磨蚀作用下,串珠前端的高出露金刚石磨粒容易产生非正常脱落。串珠磨损可分为腰鼓形状成形及腰鼓形状保持两个阶段。在切削负荷及岩屑磨蚀的共同作用下,串珠前、中、后三个部分在两个阶段的磨损表现各不相同。串珠前端是以岩屑磨蚀为主,而对于串珠中端,则是主要承受切削负荷。串珠后端两种作用的影响程度相对较弱。     

Mechanisms of material removal and subsurface damage in fixed-abrasive diamond wire slicing of single-crystalline silicon

Single-crystal silicon was sliced using a newly developed high-speed fixed-abrasive dicing wire saw. The effects of diamond grit size, wire speed, and number of slicing cycle on the surface roughness and subsurface damage of the workpiece were investigated by surface profiling, Raman spectroscopy and cross-sectional transmission electron microscopy. It was found that by using finer diamond grits and increasing the sawing cycles, the depth of micro dents and saw marks was reduced significantly, and in turn, the surface roughness was improved. A transition from brittle mode to ductile mode machining was confirmed from chip morphology observation when reducing the grit size. The subsurface damaged layers were composed of amorphous layers, dislocated layers with grain boundaries, as well as micro cracks. The smooth surface regions were dominated by amorphous silicon; while within the saw marks, a mixture of amorphous and metastable silicon phases was detected. Inside the micro dents, however, single-crystal silicon was predominant. Furthermore, the significance of silicon amorphization and poly-crystallization was strongly dependent on the wire speed. The higher the wire speed, the less the amorphous and polycrystalline layer. The present study provides comprehensive insights into the surface formation mechanism which is important for process optimization of high-speed and low-damage slicing of single-crystal silicon.     

环形电镀金刚石线锯的研制

研制了一种新型环形电镀金刚石线锯 ,介绍了锯丝基体的制备及锯丝电镀工艺。锯切试验表明该金刚石线锯具有锯切表面质量好、锯切效率高、出材率高等优良性能 ,尤其适合贵重硬脆材料以及各向异性复合材料的切割加工。