颗粒增强铝复合材料切削力特性研究

通过SiCp／2024铝复合材料的车削试验,阐述了刀具材料、切削用量(v0、f、αp)及颗粒增强相SiCp含量、粒度等因素对切削力的影响规律,发现了当增强相体积分数V1约为17％～18％以上时,用K类硬质合金刀具切削会出现切深分力Fp、进给分力F1大于主切削力Fe的现象,且SiCp含量越高差值越大,并提出用切削力系数K表述这一现象。认为K类硬磕合金可用于粗加工、半精加工,且加工表面会出现“熨平”现象。从切削力这一因素来看,PCD是精加工颗粒增强铝复合材料的最佳刀具材料。     

颗粒增强铝基复合材料振动切削力特性的研究

颗粒增强铝基复合材料由于其优越的性能,在许多领域有广泛应用。但是由于它是两相材料,加工性能差。文章使用PCD刀具,采用超声振动切削方式,主要考察了刀具几何参数和切削用量对三向切削力的影响规律。为该材料的加工工艺研究提供了依据。实验发现刀尖圆弧半径变化时,切削力出现拐点。切削速度超过一定值后,切削力反而减小。背吃刀量在一定范围时,背吃刀力大于主切削力。     

纤维增强铝基复合材料研究进展

综述了纤维增强铝基复合材料研究进展，概述了纤维增强体的性能特点和制备方法，简介了纤维增强铝基复合材料的主要制造方法，并对几种典型的纤维增强铝基复合材料的特性、制造工艺和研究应用现状进行了论述。     

碳化硅增强铝基复合材料切削加工研究进展

针对近年来Si Cp/Al复合材料的切削加工研究状况,对Si Cp/Al复合材料在切削加工中的切削力、刀具磨损、表面完整性、切屑与缺陷形成机理、加工温度、仿真模拟及特种与复合加工技术等方面进行分析与总结,以便更全面地了解碳化硅增强铝基复合材料的切削加工研究进展。     

碳纳米管增强铝基复合材料的研究进展

介绍了碳纳米管增强铝基复合材料的研究现状,通过对比不同制备工艺以及碳纳米管增强铝基复合材料的抗拉强度、硬度、伸长率等力学性能,总结了粉末冶金法、高能球磨法、热喷涂法以及其它新技术的优缺点,同时阐述了复合材料制备过程中存在的问题及解决方法;此外还介绍了碳纳米管的强化机制;最后讨论了碳纳米管增强铝基复合材料未来的发展方向和研究重点。     

TiC颗粒增强铝基复合材料耐磨性能研究

实验结果表明：在铝及其合金中添加TiC颗粒可明显提高材料的抗磨损性能,且磨损性能与材料的硬度之间没有必然的联系。TiC颗粒增强铝基复合材料的磨损表面既有磨粒磨损的特征形貌,又具有粘着磨损的特征产物,磨损过程中两种机理共同发生作用。     

超声振动钻削SiC颗粒增强铝基复合材料时的切削力研究

采用超声振动钻削的方法对金属基复合材料进行孔加工。在自行研制的超声钻削设备的基础上使用不同材质的硬质合金麻花钻,对不同含量的SiC颗粒增强铝基复合材料(SiCp/Al)进行了普通钻削与超声振动钻削的对比试验,并分析比较了加工中切削力的变化规律。试验表明,超声振动钻削可以降低切削力,在一定程度上改善钻削机理。     

SiC粒子增强铝基复合材料的磨损行为

采用铸造法制备１０ｖｏｌ％和２０ｖｏｌ％的ＳｉＣ铝基复合材料。在不同载荷下对基体合金和复合材料进行了干摩擦条件下的磨损试验。结果表明：ＺＬ１０１－ＳｉＣ复合材料显示出良好的耐磨性。在较高载荷下均匀分布的ＳｉＣ粒子使磨机上形成较高含铁量的富铁层，能延缓粘着磨损的发生。     

铝基碳化硅复合材料的精密磨削研究

粗指向机构具有激光通信载荷的粗指向和跟踪功能,粗指向机构中的轴系部件采用体积分数为25％的铝基碳化硅复合材料.论述了铝基碳化硅复合材料的磨削加工现状,以粗指向机构中的方位主轴为例,分析了圆度误差的组成和产生原因,并提出了减小圆度误差的措施,由此实现了铝基碳化硅复合材料的精密磨削.     

颗粒增强铝基复合材料焊接技术的发展

针对目前颗粒增强铝基复合材料在焊接方面存在的一些技术问题,简要介绍了国内外几种适用于铝基复合材料焊接的新技术,主要有非真空扩散焊接、非夹层液相扩散焊接、等离子喷涂焊接、激光诱发反应焊接、刷镀镍涂层激光焊接、搅拌摩擦焊和电容储能放电焊接等。     

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.     

铝合金高速切削表面粗糙度的实验研究

使用硬质合金刀具对LY12高强度铝合金进行了高速精密切削试验。研究了切削条件、切削用量对加工表面粗糙度的影响。高速切削试验表明:提高切削速度与减小进给量有利于改善铝合金工件的加工表面质量;当切削速度超过某一范围后,随着切削速度的进一步提高,加工表面粗糙度的降低并不明显。     

铸态SiCW/Al复合材料的表面喷丸强化

对铸态20％SiCw/6A02Al复合材料进行了表面喷丸处理，测量了表层基体残余应力的分布情况， 建立了复合材料表层基体屈服强度的X射线试验方法，探讨了其表层喷丸强化效应。结果表明：经喷丸处理后复合材料表层基体呈现出较大残余压应力状态，X射线衍射峰半高宽度即显微组织强化效应明显增大，导致复合材料表层基体屈服强度提高。     

微创钻骨系统切削参数对切削力与温度的影响

股骨头切削手术是一种常见的治疗股骨头坏死的手术方法,具有自动钻削,微创伤等特点的先进手术器械解决方案越来越多的代替传统人工方式,其中,钻头的优化设计和骨骼材料的切削特性的分析方法对该类器械设计方案具有理论和指导意义.研究了一种新型的用于切削手术的微创钻扩系统,在相关实验平台上,研究了机构中钻头的设计参数、轴向力和转速之间的关系,在此基础上建立对钻扩系统的机械设计中的参数设定和优化的实验与理论依据.     

Experimental investigation of the influence of adhesion on the frictional conditions in the cutting process

This paper presents the results of an experimental study on the influence of adhesion on the tribological characteristics of the tool-chip interface. It was established that under orthogonal cutting conditions both the high interface temperature and severe plastic deformation result in relatively strong adhesion between steel and uncoated carbide. In particular, the molecular–mechanical theory of friction was applied to estimate the shear strength of the local adhesive junction, and to divided the rake face friction into two terms—an adhesion term (the interfacial coefficient of friction) and the deformation term. It should be pointed out that the data obtained provide a new approach to analyzing the frictional behaviour of the cutting process.     

截止阀特性测试与研究

根据JB／T5296－91的有关规定,对2种结构的截止阀压差－流量关系进行了测试。通过对试验数据进行双曲回归,计算出2种结构阀门在各种开度下的流阻系数,并绘制了压差－流量及流阻系数－开度关系图。     

Experimental investigation and optimisation in drilling of GFRP composites

Glass fibre-reinforced polymer (GFRP) composite materials are one of the important materials and are economic alternative to engineering materials because of their superior properties. This paper presents an effective approach for the optimisation of drilling parameters with multiple performance characteristics based on the Tagugch’s method with grey relational analysis. Taguchi’s L₁₆, 4-level orthogonal array has been used for the experimentation. The drilling parameters such as spindle speed and feed rate are optimised with consideration of multiple performance characteristics, such as thrust force, workpiece surface roughness and delamination factor. Response table and response graph are used for the analysis. The analysis of grey relational grade indicates that feed rate is the more influential parameter than spindle speed. The results indicate that the performance of drilling process can be improved effectively through this approach.     

An experimental investigation on the process parameters influencing machining forces during milling of carbon and glass fiber laminates

Milling is the most feasible machining operation for producing slots and keyways with a well defined and high quality surface. Milling of composite materials is a complex task owing to its heterogeneity and the associated problems such as surface delamination, fiber pullout, burning, fuzzing and surface roughness. The machining process is dependent on the material characteristics and the cutting parameters. An attempt is made in this work to investigate the influencing cutting parameters affecting milling of composite laminates. Carbon and glass fibers were used to fabricate laminates for experimentations. The milling operation was performed with different feed rates, cutting velocity and speed. Numerically controlled vertical machining canter was used to mill slots on the laminates with different cutting speed and feed combinations. A milling tool dynamo meter was used to record the three orthogonal components of the machining force. From the experimental investigations, it was noticed that the machining force increases with increase in speed. For the same feed rate the machining force of GFRP laminates was observed to be very minimal, when compared to machining force of CFRP laminates. It is proposed to perform milling operation with lower feed rate at higher speeds for optimal milling operation.     

PCD刀具超声振动切削金属基复合材料SiCp/Al的特性研究

试验研究了普通和超声切削新型颗粒增强金属基复合材料SiCp/Al的切削特性 ,得到超声振动切削该材料的切屑形态、切削力变化规律     

On modeling of cutting forces in micro-end milling operation

Micro-end milling is used for manufacturing of complex miniaturized components precisely in wide range of materials. It is important to predict cutting forces accurately as it plays vital role in controlling tool and workpiece deflections as well as tool wear and breakage. The present study attempts to incorporate process characteristics such as edge radius of cutting tool, effective rake and clearance angles, minimum chip thickness, and elastic recovery of work material collectively while predicting cutting forces using mechanistic model. To incorporate these process characteristics effectively, it is proposed to divide cutting zone into two regions: shearing- and ploughing-dominant regions. The methodology estimates cutting forces in each partitioned zone separately and then combines the same to obtain total cutting force at a given cutter rotation angle. The results of proposed model are validated by performing machining experiments over a wide range of cutting conditions. The paper also highlights the importance of incorporating elastic recovery of work material and effective rake and clearance angle while predicting cutting forces. It has been observed that the proposed methodology predicts the magnitude and profile of cutting forces accurately for micro-end milling operation.