数控异形泡棉切割机的运动控制

本文主要分析了泡棉切割加工的工艺要求,以及数控加工的轨迹控制,确立了数控异形泡棉切割机的位置控制系统的方案,研究了其硬件配置和软件结构。本课题的研究是数控异形泡棉切割机研制成功的关键,该切割机已研制成功,并交付用户使用,切削效果好。     

GCr18Mo轴承套圈硬态数控车削技术的研究

以GCr18Mo轴承套圈为车削对象,采用陶瓷刀具在多功能数控车床上进行了硬态车削试验研究,对硬态数控车削用陶瓷刀具几何参数的合理选用、切削参数的选择进行了实际探讨,研究了硬态数控车削对轴承套圈表面质量的影响。     

滚珠丝杠滚道硬车加工技术研究

以CBN刀具技术的突破和数控硬车机床的研发成功为基础,针对滚珠丝杠螺纹滚道特点,研究其硬车工艺方法、专用机床技术、CBN刀具技术,并通过进行切削试验,获得合理切削参数,实现螺纹滚道粗加工以硬车削代替磨削,提高生产效率,降低成本。     

大型、重载、精密滚珠丝杠副设计及硬旋铣加工装备关键技术（续）

四、大型螺纹高效、精密数控旋风铣削加工装备关键技术1．大型螺纹绿色高效切削机理围绕加工机理与特性研究,拟解决的关键科学问题包括：大型精密螺纹绿色高效硬旋铣切屑形成和表面形貌的形成机理、大型螺纹高速硬铣削过程动力学特性与模型、大型螺纹高速硬铣削工艺基础研究。高速旋风硬铣削是解决这类螺纹的高效加工的有效途径,但其切削机理、工艺基础的研究不足,严重制约了我国相关技术的发展,为了达到绿色制造的目的、将干切削技术用于螺纹硬旋铣。大型螺纹高速硬铣削不仅是高速切削,还是干式重载切削,     

翼片的数控加工工艺研究

通过对翼片类零件的结构分析,指出了装夹定位方式、加工方法及切削参数是影响其加工质量的主要因素,并结合实例,提出了3种因素的选择方法,为翼片的加工提供了质量保证。在翼片的数控加工工艺研究过程中,涉及到零件加工过程建模技术、基于正交试验法的切削参数优化技术以及淬硬钢的高速切削技术,这些技术的应用分析对装夹定位方式、加工方法及切削参数的选择效果明显,所得结论与实际加工检验数据基本一致,对翼片的加工具有实际指导意义。     

加减速控制算法及其对数控加工的影响

研究了数控加工加减速控制的指数算法，并分析了稳态与动态位置误差产生的数学模型。在此基础上，还讨论了它们对螺纹切削和转角切削等典型数控加工误差的影响，最后给出了消除或减少加工误差的方法。     

硬态切削用刀具技术最新进展

作为具有广泛应用前景的加工工艺,硬态切削以其加工柔性、经济性和环保性等优点,在汽车、模具等行业被广泛应用。该工艺成功实施的关键因素是刀具的合理选择及其性能的发挥。该技术近年来发展迅速,诸多人员和机构对硬态切削工艺所用的刀具进行了深入的研究,有效地推动了该工艺的应用。本文综述了近年来针对硬态切削工艺用刀具的刃型结构、材料选择、刀具涂层等方面的研究成果,并分析了目前被广泛采用的典型刀具型号及其性能,从而为硬态切削工艺用刀具的选用及设计提供指导作用。     

数控干式切削中PCBN刀具的选择

根据数控干式切削对PCBN刀具的基本要求,介绍了PCBN刀具的性能特点,在数控干式切削中选用PCBN刀具时应考虑刀具结构、结合剂种类、CBN含量、CBN粒度、刀具几何参数和切削用量,充分发挥PCBN刀具的最大加工效益.     

现代数控车刀结构设计技术研究

在对金属材料进行切削加工过程中,刀具刃口部分的宏观和微观几何结构对提高工件加工精度、提升切削效率以及完善延长刀具寿命等方面都起着重要的作用。现代数控车刀相对于传统刀具,基本是以可转位刀片为主体的可拆卸结构,在设计可转位车刀时,应对被加工件的材料属性、切削技术条件以及工件几何精度等因素进行统筹考虑,在刀片的宏观和微观结构以及刀杆本身几何外形两方面进行综合分析,从而为高性能数控刀具的结构设计奠定基础。通过对现代数控可转位刀片及刀杆几何结构进行综合研究分析,提出了高性能可转位刀具结构的工程设计方法,可为现代数控刀具的创新设计提供新的思路。     

基于PCBN刀具的陶瓷模具数控加工

简述了PCBN刀具的性能和制造方法，并分析了陶瓷模具的特点和加工工艺，提出了用PCBN刀具硬态数控切削加工复杂陶瓷模具型面的工艺，实际应用证明利用PCBN刀具在数控机床上可以有效经济地对一些复杂型面的产品和模具进行加工。     

高速硬态切削工件表层显微硬度与白层研究

高速和硬态切削使得工件已加工表面及其表层中出现特有的现象.研究结果表明,切削速度和材料硬度是决定高速和硬态切削工件已加工表面及其表层结构形成的主要影响因素,切削热使被切削材料产生高温软化,刀具挤压摩擦使被切削材料变形加剧,工件表层材料显微硬度分布发生改变,出现了硬脆的白层组织,白层组织的出现将对零件的使用将造成不利影响.随着切削用量和材料硬度增大,切削变形增大,切削温度升高,白层厚度增大,工件表层材料显微硬度提高.抑制白层组织产生的措施是对工件降温.     

Finite element modeling and simulation in dry hard orthogonal cutting AISI D2 tool steel with CBN cutting tool

The influences of cutting parameters on temperature, stress, and shear angle during dry hard orthogonal cutting (DHOC) of D2 tool steel (62?±?1 HRC) are investigated in this paper. Temperature and stress are considered the most important aspects to be taken into account in dry hard machining; however, dry hard machining is a complex process, and the temperature fields and residual stress are the most difficult to be measured. Up to now, only very few studies have been reported on influences of cutting parameters on shear angle, temperature, and stress of AISI D2 tool steel (62?±?1 HRC). In this paper, the Johnson–Cook model is utilized to propose a finite element (FE) model. The FE model is properly calibrated by means of an iterative procedure based on the comparison between experimental resultant forces obtained from literatures and simulated resultant forces. At last, this FE model is utilized to predict the influences of cutting speed and depth of cut on temperature fields and residual stress within a workpiece, cutting tool edge temperature, and shear angle during DHOC hardened AISI D2 tool steel (62?±?1 HRC) and validated by experimental results. As shown in this investigation, it is also possible to properly analyze the influences of cutting parameters on the cutting mechanism for industrial application.     

“Peel cutting” – A new cutting method for difficult-to-cut workpieces with hard oxide surfaces

A new cutting method named “peel cutting” is proposed in this research to suppress notch wear in machining of metals with hard oxide surfaces. In general, metals are produced by hot deformation processes like rolling, forging, and extrusion, which cause hard oxide surfaces called scales on their surfaces. These hard scales need to be removed first in machining of precision parts. However, the machining causes the severe notch wear at the depth-of-cut position, where the tool contacts the hard scale. To solve this problem, the proposed peel cutting avoids this direct contact between the tool and the scale by inclining the end cutting edge at an extremely large inclination (oblique) angle. This extremely oblique cutting changes the material flow and generates a “burr-like chip”. In the proposed cutting method, the tool contacts only soft non-oxide metal under the scale during cutting. Cutting of titanium alloy Ti–6Al–4V is conducted by modifying commercial tools to provide extremely large inclination angles, and it is clarified that an inclination angle of 70 deg or greater is required to realize the proposed cutting. Tool wear in the proposed cutting of the alloy with a hard scale is also observed in comparison with the ordinary cutting, and the result verifies that the notch wear can be suppressed successfully by the proposed peel cutting.     

车床式泡沫塑料切割台设计与实现

车床式泡沫塑料切割台,其外形结构与车床相似。在泡沫坯体夹具和切割刀夹具以及引电机构共同作用下,用电热丝刀具切割泡沫材料。刀架承载着切割刀能在垂直于XZ和YZ平面方向上作旋转切割,也能在横向和纵向方向上作平面切割,还能调整刀架角度作斜面切割。由于有尺寸定位机构和走刀量的控制机构,使得切割过程能按设定的尺寸准确加工,产品表面光滑平整。毛坯夹具带有锁紧机构,能控制毛坯在YZ平面上作任意角度旋转。设备采用的刀具有不同种类,分为旋转切割刀、平面切割刀以及阶梯孔切割刀,以方便切割不同结构的泡沫制品。     

高速切削技术在难加工材料上的应用

通过对金属传统切削机理与高速切削机理的比较，从切屑成形原理、切削热的产生分布及传递、刀具磨损、表面质量、生产率的提高等各方面来阐述高速切削技术在难切削材料中的应用。     

Laser cutting of small diameter hole in aluminum foam

The International Journal of Advanced Manufacturing Technology - Laser cutting of a small diameter hole into aluminum foam is carried out, and thermal stress field developed in the cutting section...     

单线切割机中的张力控制技术

介绍了用于单线切割机设备中,对于钢丝的张力闭环控制技术。为了提高切割表面的光洁度及精度,采用钢丝,并在钢丝上喷粘金刚砂进行来回切割,钢丝的张力精度直接影响切割表面的精度,因此张力的控制精度尤为重要。系统采用前后两端分别控制张力的方式,以保证整个张力的平稳。     

An experiment study of hard coating and cutting fluid effect in milling aluminum alloy

This paper investigates the cutting performance of a tungsten carbide end mill with hard coating and a sulfurous boric acid ester cutting fluid in milling A6061P-T651 aluminum alloy. The experiments were conducted to compare the milling force responses and flank wear under various cutting conditions. The results indicate that adding sulfurous boric acid ester cutting fluid decreases tool wear by 12.5% for hard coating tungsten carbide end mills and decreases the milling force by 10%. Besides, the average values of side and end flank wear of TiAlN-surface multilayer end mills can be decreased 38.7% and 68.7% respectively compared with uncoated and dry end mills.     

The cutting tool stresses in finish turning of hardened steel with mixed ceramic tool

Precision hard machining is an interesting topic in manufacturing die and mold, automobile parts, and scientific research. While the hard machining has benefit advantages such as short cutting cycle time, process flexibility, and low surface roughness, there are several disadvantages such as high tooling cost, need of rigid machine tool, high cutting stresses, and residual stresses. Especially, tool stresses should be understood and dealt with to achieve successful performance of finish hard turning with ceramic cutting tool. So, the influence of cutting parameters on cutting stresses during dry finish turning of hardened (52 HRC) AISI H13 hot work steel with ceramic tool is investigated in this paper. For this aim, a series finish turning tests were performed, and the cutting forces were measured in tests. After literature procedure about finite element model (FEM), FEM is established to predict cutting stresses in finish turning of hardened AISI H13 steel with Ceramic 650 grade insert. As shown, effect of the cutting parameters on cutting tool stresses in finish turning of AISI H13 steel is obtained. The suggested results are helpful for optimizing the cutting parameters and decreasing the tool failure in finish turning applications of hardened steel.     

Topography and microstructure of the cutting surface machined with abrasive waterjet

Abrasive waterjet (AWJ) technology has been widely used for cutting materials in precision machining. The present paper reports the surface topography and microstructure of the cutting surfaces machined by AWJ. Four different kinds of ductile metallic materials were used for preparation of specimens. With the AWJ processing technique, smooth surfaces were easily obtained with a lower surface roughness about 2 to 3 μm. By comparing the microhardness of the specimens with the control surface sample obtained by wire electrodischarge machining, it is found that there is no heat-affected zone on the cutting surfaces machined by AWJ. By observing the surface morphology and microstructure, the features of friction and wear marks are revealed. The results show that a smooth cutting surface is more easily obtained on hard materials, while erosions on soft material surfaces are more serious. All scratches have a clear consistent direction, under the action of mechanical abrasive wear.