共查询到20条相似文献，搜索用时 15 毫秒
1.
The hole-making process in stack materials consisting of carbon fiber reinforced plastics(CFRP) and Ti-6Al-4V remains a critical challenge. In this paper, an experimental study on the helical milling of CFRP/Ti-6Al-4V stacks was conducted by using two different machining strategies. Helical milling strategyⅠ machines both materials with identical machining parameters, while machining strategyⅡ uses two sets of machining parameters to machine each material. Helical milling performance was evaluated by the following indicators: tool life, cutting forces, hole quality(including diameter deviation, roundness, roughness, and hole edge quality). The results demonstrate that helical milling strategy Ⅱ outperformed strategy Ⅰ, leading to longer tool life(up to 48 holes), smaller cutting forces and better hole quality with higher geometric accuracy and smoother surface finish(Ra≤ 0.58 μm for Ti-6Al-4V and Ra ≤ 0.81 μm for CFRP), eliminating the need for reaming or de-burring. 相似文献
2.
In this paper, a series of experiments were performed by high speed milling of Ti-6.5Al-2Zr-1Mo-1V (TA15) by use of polycrystalline diamond (PCD) tools. The characteristics of high speed machining (HSM) dynamic milling forces were investigated. The effects of the parameters of the process, i.e., cutting speed, feed per tooth, and depth of axial cut, on cutting forces were studied. The cutting force signals under different cutting speed conditions and different cutting tool wear stages were analyzed by frequency spectrum analysis. The trend and frequency domain aspects of the dynamic forces were evaluated and discussed. The results indicate that a characteristic frequency in cutting force power spectrum does in fact exist. The amplitudes increase with the increase of cutting speed and tool wear level, which could be applied to the monitoring of the cutting process. 相似文献
3.
KHAN M.M.A DHAR N.R. 《浙江大学学报(A卷英文版)》2006,7(11):1790-1799
In all machining processes, tool wear is a natural phenomenon and it leads to tool failure. The growing demands for high productivity of machining need use of high cutting velocity and feed rate. Such machining inherently produces high cutting temperature, which not only reduces tool life but also impairs the product quality. Metal cutting fluid changes the performance of machining operations because of their lubrication, cooling and chip flushing functions, but the use of cutting fluid has become more problematic in terms of both employee health and environmental pollution. The minimization of cutting fluid also leads to economical benefits by way of saving lubricant costs and workpiece/tool/machine cleaning cycle time. The concept of minimum quantity lubrication （MQL） has been suggested since a decade ago as a means of addressing the issues of environmental intrusiveness and occupational hazards associated with the airborne cutting fluid particles on factory shop floors. This paper deals with experimental investigation on the role of MQL by vegetable oil on cutting temperature, tool wear, surface roughness and dimen- sional deviation in turning AISI-1060 steel at industrial speed-feed combinations by uncoated carbide insert. The encouraging results include significant reduction in tool wear rate, dimensional inaccuracy and surface roughness by MQL mainly through reduction in the cutting zone temperature and favorable change in the chip-tool and work-tool interaction. 相似文献
4.
从切削力、刀具磨损、表面粗糙度3方面进行实验研究,找出P20钢与718钢的切削共性,从而得到预硬型塑料模具钢的加工特性.结果表明,对主切削力影响较大的是切削深度和进给量;当切削速度超过80～90 m/min时,表面粗糙度明显降低;与45钢相比,这类模具钢的刀具耐用度较差,且刀具主要磨损形态是磨料磨损. 相似文献
5.
李海斌张晓波石林爽张曼婷 《福建工程学院学报》2021,(4):360-364
采用固体渗剂包埋渗法对Ti-6Al-4V钛合金进行硼-稀土共渗处理,并利用超声振动空蚀机研究分析试样在去离子水中的空蚀性能。结果表明,硼-稀土共渗在Ti-6Al-4V合金表面获得均匀致密的表面渗层。表面渗层具有很高的显微硬度,与基体冶金结合,其主要由TiB2、TiB化合物层和B原子固溶于α-Ti的扩散层构成。稀土元素La的添加,提高渗硼效率,使试样表面渗层厚度增加,显微硬度显著提高,材料的抗空蚀性能得到显著改善。 相似文献
6.
Aiming at the surface integrity of titanium alloy Ti-6Al-4V in high speed side milling, a series of side mill- ing tests were carried out with uncoated carbide milling cutter at various milling speeds. Surface roughness, residual stress, subsurface microstructure and microhardness variations were investigated. The surface roughness measurement results present that the milling speed from 80 to 120 m/min fails to produce better and more stable roughness values compared with the result obtained from 320 to 380 m/min. The residual stresses in the feed direction and axial depth of cut direction are in similar trends for the two milling speed levels mentioned above. Moreover, the residual stress pro- duced at 320 to 380 m/min is lower and more stable than that at 80 to 120 m/min. The microstructure analysis shows that the volume of β phase in the near surface becomes smaller and the deformation of β phase in the near surface be- comes obvious with the increase of the milling speed. Subsurface microhardness variation was observed down to 200 μm below the machined surface at 80 to 120 m/min and down to 160 μm at 320 to 380 m/min. It is concluded that better surface integrity and higher material removal rate can be obtained at 320 to 380 m/min than at 80 to 120 m/min. 相似文献
7.
In this work, the orthogonal cutting experiments on Ti-6Al-4V alloy were conducted at different cutting speeds(10—160 m/min)and feed rates(20—160 μm/rev). The tool-chip contact length was measured by the track of tool rake face; meanwhile, the chip morphology caused by the localized and overall chip deformation was characterized by the degree of segmentation and the chip compression ratio, respectively. These parameters were analyzed and calculated according to the segmented chip morphology. In addition, three modified models considering the overall chip deformation and the localized deformation of adiabatic shear band were proposed, and the constants of the models were calculated by the genetic algorithm optimization. Considering the overall and localized chip deformation, the value and variation trend of the tool-contact length predicted by these three models agreed well with the experimental results. 相似文献
8.
吕凯 《通化师范学院学报》2013,(12):46-48
切削刀具的质量是机械加工设备长期有效运行的决定性因素.切削所产生的热量是铣刀片磨损和破损产生的重要因素,揭示刀具破损磨损的产生机理的重要手段是研究切削热和切削温度的变化规律.针对这一问题,用元胞自动机思想,建立以元胞自动机理论研究铣刀片在切削过程中温度影响的评价准则,来研究温度的变化对切削刀具的影响. 相似文献
9.
AWAD Samir Hamid 《重庆大学学报(英文版)》2005,4(1)
1 Introduction Weight saving materials such as aluminum and its alloys are becoming increasingly important and have been attracting increasing attention over the past decade, specially in the automotive, aerospace and chemical industries, and electrical devices because of their high strength-to-weight ratio, high electrical and thermal conductivities, processability and recyclability and good resistance to degradation in some corrosive environments [1,2]. In the automotive industry, there is d… 相似文献
10.
通过对立铣刀侧铣平面、凸凹圆弧面时,刀具旋转运动和进给运动的轨迹包络几何分析,计算出顺铣、逆铣时不同的残留高度,结果显示逆铣加工得到的表面粗糙度优于顺铣.采用顺铣和逆铣2种方法对平面、凸凹圆弧面进行加工,及表面粗糙度的对比和数据分析,也证实逆铣加工得到的表面粗糙度较好. 相似文献
11.
针对难加工球墨铸铁材料进行高速铣削工艺参数优化研究,设计了四因素四水平正交实验,以获得铣削用量对加工过程力和表面粗糙度的影响关系,并利用多元回归分析建立铣削分力和粗糙度的经验模型。研究结果表明:每齿进给量对粗糙度值影响最为显著,铣削参数设置不同,产生的铣削分力不同,背吃刀量对铣削分力影响最大。针对最小铣削力与最小粗糙度的目标,分别得出最优的铣削用量参数。 相似文献
12.
刀具结构创新是实现高效加工的有效途径之一 总被引：1，自引：1，他引：0
徐进 《广东轻工职业技术学院学报》2008,7(4):7-10
刀具结构创新是提高切削效率,实现高效加工的有效手段之一。以切削变形和切削摩擦两个基本问题为出发点,对刀具几何结构进行创新改造,使第Ⅲ变形区中材料的延展变形实现向着低应力区域的多维塑性流动。对外圆车削试件的已加工表面和对刀具检测表明,创新刀具能够有效地降低工件表面粗糙度,提高尺寸精度,使已加工表面层中保持残余压应力;减轻刀具的磨损,提高刀具耐用度。 相似文献
13.
研究了球头铣刀高速铣削过程铣削力建模与仿真。考虑了作用在前、后刀面上的正压力和摩擦力,建立了高速铣削加工中局部铣削力模型,在上述基础上建立了整体铣削力的模型。通过铣削实验,验证了所建模型的正确性。 相似文献
14.
NAK80材料曲面高速铣削表面质量实验研究 总被引：1，自引：0，他引：1
通过实验，研究了模具制造业中常用的NAK80材料的表面粗糙度形成及曲面高速加工工艺参数的选择策略，分析了NAK80材料在高速铣削加工中以铣代磨的切削机理。结果表明，NAK80材料适合高速加工，在未来将成为高级橡塑模具的主要应用材料。 相似文献
15.
Laser shock processing (LSP), also known as laser peening, is a novel surface treatment technique in the past few years. Compressive
residual stresses which imparted by LSP are very important for improving fatigue, corrosion and wear resistance of metals.
Finite element analysis (FEA) simulation using ABAQUS software has been applied to predict residual stresses induced by LSP
on Ti-6Al-4V titanium alloy with laser pulse duration 30 ns and water confined ablation mode. The residual stress field generated
by different shape laser spots was studied, and the square laser spot is shown the most suitability for avoiding stress lack
phenomenon and overlapping LSP. Surface residual stresses and plastically affected depth within single square spot both increased
with the increase of laser intensity and laser shock times. Furthermore, compared with circle and ellipse spot, the residual
stress distribution in overlapping square spots is very uniform only with small overlapping ratio. LSP with square spot can
process advantageous residual stress field, and this technique will be used widely. 相似文献
16.
我们所研制的含钙易切钢(40 CrCa)的可加工性具有一个明显的特点,即在某一切削速度范围内,这种钢的可加工性是随着切削速度的提高而改善的。当切削速度V≈200米/分时,可加工性达到最佳状态。此时刀具的耐用度为切削普通钢(40Cr)时的8倍。 这种易切钢的可加工性特别好的原因在于:用钨、钛、钴类硬质合金刀具(YT15)以高的切削速度切削这种钢时,钢中的球状氧化夹杂物会软化,并且沉积在刀具表面上形成一层薄膜,这层薄膜对刀具的磨损有阻碍作用。 相似文献
17.
球头铣刀铣削过程的物理建模与仿真 总被引：1，自引：0，他引：1
给出了球头铣刀刃线几何模型,采用理论切削力分析与实验-系数识别相结合的方法,建立了新的螺旋刃球头铣刀的铣削力模型;建立了考虑刀杆柔性的球头铣刀铣削振动模型;考虑刀具动态变形和工件表面波纹对切削厚度的再生反馈,建立了球头刀铣削动力学模型,对动态铣削过程进行了仿真,证明离线仿真可以对铣削过程动特性做出准确的预测. 相似文献
18.
19.
Compacted graphite cast iron (CGI) has been the material for high-power diesel engines recently, but its increased strength causes poor machinability. In this study, coated and uncoated carbide tools were used in dry milling experiment and FEM simulation to study the machinability of CGI and wear behaviour of tools. The experimental and FEM simulation results show that coated tool has great advantage in dry milling of CGI. SEM and EDS analysis of tool wear indicate the wear morphology and wear mechanism. Adhesive wear is the main mechanism to cause un-coated tool wear, while abrasive wear and delamination wear are the main mechanism to cause coated tool wear. Stress and temperature distribution in FEM simulation help to understand the wear mechanism including the reason for coating peeled off. 相似文献
20.
通过作图比较,研究了不同尺寸刀具的切削粗糙度要求对刀具轨迹的影响,又进一步通过对曲面特征细分进行研究,并举例说明了如何利用MasterCAM的虚拟仿真技术和自动编程技术,以实现数控铣削加工刀具路径优化。 相似文献