基于纳秒光纤激光器的彩色打标工艺研究

采用脉冲光纤激光打标装置,设置不同的激光打标工作参数,对不锈钢样品进行打标,然后对结果进行分析。通过改变激光打标扫描速度、激光打标功率等参数,得出不同激光能量可以加工出不同的打标产品颜色。     

羟基磷灰石功能梯度材料的激光涂层及材料性能研究

针对将羟基磷灰石涂覆在钛合金基底表面的问题,将三层具有不同配比的羟基磷灰石和纯钛混合物预敷在钛合金表面,利用激光覆熔法依次对预敷层进行扫描,形成了具有梯度结构的羟基磷灰石复合材料.通过实验分析了复合材料的微观材料结构、机械性能及生物兼容性,并分析了激光工艺参数对复合涂层材料性能的影响.研究结果表明,羟基磷灰石功能梯度材...     

FDM成型后ABS材料表面质量车削实验研究

ABS材料作为一种热塑性材料,常用于熔融沉积成型(FDM)工艺等多个领域。通过对不同成型角度和分层厚度的FDM实验研究可知,运用该技术成型的ABS材料表面质量普遍较差。为了解决这一问题,采用增减材混合加工方法,选用合适的FDM成型参数组合,对FDM成型后的ABS材料进行超声振动切削实验研究,从而改善该材料的表面质量。同时,对切削实验后的结果进行极差分析,研究了切削三要素对表面粗糙度的影响规律,并通过实验对比研究了普通切削和超声振动切削ABS材料的表面形貌特征区别。     

基于激光加工的微米级平行沟槽表面润湿性实验研究

生物医用材料表面润湿性是影响其生物相容性的一个重要影响因素。通过改变激光加工工艺参数,在钛合金基底上制备不同微结构尺寸的平行沟槽结构,采用白光干涉的方法测量钛合金表面平行沟槽的轮廓形貌,分别从平行和垂直纹理方向上对静态接触角、前进角和后退角进行测量,分析材料表面微结构对润湿性的影响,并探讨微结构尺寸与能量壁垒之间的关系。     

不锈钢激光焊接工艺的研究

本文通过用300WCO_2激光器对两种不锈钢薄板材料进行激光对焊和端焊实验以及对焊接后金相组织的分析,探讨了获得材料最佳力学性能所需的激光焊接工艺参数和相应的金相组织。分析了材质、原始状态、保护气体等条件对焊接效果的影响,提出了激光特种焊接工艺的规律性。     

激光打标的失效分析及改进措施

激光打标过程中,工件上的油脂易蒸发后冷凝在滤镜上,进而造成激光打标失效,影响生产效率。通过对激光打标系统的冷凝形成机理进行分析,针对故障问题进行深入理论探讨,找出故障原因并提出有效的解决方法,希望对激光打标机的高效运用提供借鉴作用。     

不同辅助气体对薄硅钢片的激光切割影响

针对辅助气体影响激光切割现象进行研究。采用氧气、氮气、氩气作为辅助气体以300W的Nd:YAG脉冲激光切割35A470牌号的硅钢片。首先进行大量实验研究不同工艺参数对硅钢片切缝宽度及切割质量的影响,如采用不同的激光电源电流、激光脉宽、激光频率、加工速度、离焦量等参数对比分析,然后总结出这些工艺参数对激光切割硅钢片的影响规律,再研究不同保护气体对激光切割工艺参数的选择规律,最后得出使用不同保护气体的激光切割35A470牌号薄硅钢片的最佳工艺参数。     

铜-铝异种金属搭接间隙及激光焊接参数对性能影响研究

针对铜-铝异种金属激光焊接特性,采用大功率金属激光焊接器对铜-铝异种金属搭接接头进行激光焊接实验研究,研究了不同宽度的搭接间隙对铜-铝搭接接头焊接效果以及焊接拉力强度的影响。通过调整不同的激光发射功率、焊接频率及焊接速度,研究了不同焊接参数对铜-铝板材金属搭接和焊接效果影响规律,为以后铜铝激光焊接提供实验依据。     

激光标记系统供纸机构的设计

介绍了适合于工作在流水作业上激光打标系统供纸机构的设计.采用卷筒式送纸机构,使之与激光打标系统进行有机配合,符合生产节拍,且能保证走纸顺利、平稳,保障生产线的顺利进行.基于激光打标系统供纸机构的设计具有造型美观、自动化程度高、生产效率高等优点,能适应生产线的需要,目前已应用于汽车铭牌打标生产线上.投入使用后,运行稳定,达到理想效果.     

激光钎焊的温度场有限元分析

综合考虑了材料的非线性热物性特征以及焊件表面的热对流和热传导的影响后,利用ANSYS10.0软件对激光钎焊CBN在不同激光参数下的温度场进行了有限元分析,得到了激光扫描速度对温度场的影响规律,对钎焊工艺参数的选择具有指导意义.     

<Emphasis Type="Bold">Cumulative Heat Effect in Excimer Laser Ablation of Polymer PC and ABS</Emphasis>

Analysis of the thermal effect and machining properties of PC (polycarbonate) and ABS (polyacrylonitrilebutadienestyrene) polymers when ablated using a KrF excimer laser is described. PC has less thermal effect on the geometric distortion than ABS in laser ablation. The cumulative heat during laser ablation results in geometric deformation in ABS micromachining. The number of laser pulses generates a greater geometric deformation in ABS than in PC according to experimental laser ablation observations. The PC ablation rate is proportional to the laser fluence, whereas ABS shows an exponential profile. The pulse repetition rate has no significant influence on PC during laser ablation, but affects the ablated patterns in ABS. During laser ablation, PC does not produce debris on the machining patterns, but debris is produced on the machining patterns with ABS.     

Application of response surface methodology in the optimization of laser treatment in buckypaper lighting for field emission displays

Carbon nanotube field emission backlight (CNT-BLU) is promising to replace traditional backlighting devices in liquid crystal display (LCD) industry. This study reports a laser irradiation process to enhance field emission properties of buckypaper, a thin sheet of high-loading carbon nanotube network. The scanning laser treated the selected region of buckypaper to activate CNT emitters. The improvement of phosphorescence luminance intensity, uniformity, and the reduction of turn-on field were achieved by adjusting machining parameters of laser power, laser lens motion speed, laser resolution, laser beam size, and pattern orientation. Design of experiment and response surface methodology provided ways to rapidly search the feasible laser parameter setting for processing buckypaper field emitters and improving field emission properties within fewer experimental runs. 2^5?1 Fractional fracotrial design presented the initial models of five repsponses. In addition, the face-centered central composite design is applied since the 2^5?1 factional factorial design showed curvature significance. It assisted to give the scientifical insight of the following conclusions. High-energy laser treatment damages and burns the CNTs into carbon oxide materials; furthermore, it loses the effective CNTs. Low-energy laser treatment performs CNT activation and produced low field emission performance. In this study, we succeeded to apply statistical analysis methods to understand the physics and mechanics of laser-activated buckypaper field emission and, furthermore, improve, optimize, and demonstrate performance by material selection, process development, and characterization.     

Excitation of acoustic emission by laser radiation for studies of structural alterations in composites and polymers

The special features of excitation of acoustic emission (AE) by laser radiation are studied. It has been found that ruby and copper-vapor lasers reliably excite AE with an amplitude high enough to be detected. It has been shown that AE parameters of polymers have a significant sensitivity to the type of laser irradiation used for initiating local thermal destruction. The results can be used for remote acoustic calibration and initiation of local thermal destruction during AE diagnostics of thermal stability of polymers and composite materials.     

熔融挤压快速成形制件的质量分析

熔融沉积快速成形工艺能够使用ABS塑料、聚碳酸酯、尼龙基聚合物和其它一些材料建立高强度的、耐久的完全实用的原型。由于受工艺过程参数的影响，快速制件可能会出现表面缺陷和内部缺陷。对这些可能产生的缺陷进行分析，有效避免或减少它们的出现，提高快速制件的综合质量。     

无定形塑料激光透射焊接质量分析

通过测试焊接试样的拉伸剪切强度与断口形貌,检验塑料激光透射焊接的质量.阐述了激光焊接塑料的基本原理,选用了无定形的聚碳酸酯材料进行焊接工艺研究,分析了激光参数对焊缝拉伸剪切强度的影响,并采用金相显微镜观察了断口形貌.结果表明:激光塑料焊接可以得到力学性能良好的焊接试样,由于能量密度的不同,焊缝在拉伸剪切力作用下会产生不...     

不同材料的准分子激光微细加工机制

采用准分子激光加工方法,在相同的工艺参数下加工了Al2O3陶瓷、不锈钢、Q235等脆性和塑性材料。通过扫描电子显微镜(SEM)获得加工表面微观形貌图像和采用表面轮廓仪测得形貌统计参数。分析得出,准分子激光的加工机理是光化学和热效应作用等多种因素影响的综合体现;加工不同材质的材料时,准分子激光具有不同的加工机制,对于脆性材料以光解剥离(APD)为主,而对于塑性材料则以热效应为主。     

光纤激光焊接的碳排放建模与多响应评价

全球暖化的背景下,环境影响与制造质量的协同探究成为了研究热点之一。激光焊接广泛应用于汽车、航空航天、轨道交通等制造业,但其碳排放高、能量利用率低。因此,亟需对激光焊接工艺的碳排放特性进行研究,并协同焊接质量展开综合评价。通过搭建激光焊接的碳排放监测平台,分析激光焊接平台各系统(激光发生器、冷水机、机器人、保护气体系统)的碳排放特性,构建激光对接焊的碳排放模型,计算了各系统不同阶段的碳排放占比。采用最优拉丁超立方采样法,开展激光对接焊实验,将拉伸强度和焊缝完整性作为焊接性能的评价指标,分析了激光工艺参数(激光功率、焊接速度、离焦量)对碳排放和焊接性能的影响。实验结果表明,焊接速度对碳排放影响最大,而激光功率对拉伸强度和焊缝完整性的影响最大。对于三个响应指标,激光功率呈正向作用,而焊接速度呈负向作用。根据提出的多响应综合评价方法,对25组激光对接焊的实验结果进行了评分与优劣排序。提出的方法可为激光低碳制造的工程评价提供一定的参考。     

Simulation of a head slider considering a discrete track recording technology

Discrete track recording (DTR) is a new application technology that utilizes a separate physical storage disk with grooves and ridges comprised of radial and circumferential direction in order to achieve higher data transfer rates and storage densities on a hard disk drive (HDD). However, the grooves and ridges on the DTR media cause flying stability issues. Therefore, we analyze and compare the dynamic performance of a head slider with three types of DTR media in which different DTR parameters are defined, such as groove width and pitch. Prior to simulations, we propose the DTR flying height (FH) loss equation which estimates a loss of FH on the DTR media using the defined DTR parameters. The accuracy and creditability of this equation is then predicted by comparing the results of the equation to those of the simulation. Consequently, we propose a method for designing the air bearing surface (ABS) on the DTR media using the static performance of the ABS on a continuous track recording (CTR) along with the proposed DTR FH loss equation.     

Experimental investigation of laser-produced-plasma EUV source based on liquid target

1Introduction LPPsourcesholdgreatpromiseasbright sourcesofextreme ultraviolet(EUV)andsoft X rayradiationforapplicationssuchasprojec tionlithography[12],microscopy[3].However,withLPPsource,theapplicabilityisrestricted duetotheemissionsofdebris,whichmaydam agesensitivemetrologycomponentsclosetoLPP source.Toreducethedebris,methodsconcen tratingontwoaspectshavebeenappliedbefore theappearanceofgasandliquidtargets.Oneas pectistoreducetheamountofdebris,theother istointerdictthedebrisfromreaching…     

Repeatability of linear and radial dimension of ABS replicas fabricated by fused deposition modelling and chemical vapor smoothing process: A case study

In this research work, an effort has been made to study the influence of fused deposition modelling (FDM) and chemical vapor smoothing (CVS) process parameters on the selected linear and radial dimension as well as on repeatability of acrylonitrile butadiene styrene (ABS) replicas as a case study. The study highlights that orientation of parts on FDM build platform, part density (part interior style) and interaction between these two parameters significantly affect the accuracy of selected dimensions. Shrinkage has been observed in the selected radial dimension of the prototypes, but there is a positive deviation in the linear dimension from the desired value. The CVS process reduces both the dimensions slightly due to reflow of the material. Optimum parameter settings that were different for both linear and radial dimensions have been investigated using Taguchi’s L18 orthogonal array. The IT grades of ABS replicas prepared by this combined process were found to be consistent with the permissible range of tolerance grades as per ISO standard UNI EN 20286-I (1995) and DIN 16901 for plastic materials. Finally, optimum level of process parameters that simultaneously minimizes the deviation in both the dimensions have been found out using response optimization module of Minitab 17 software and the results obtained have been verified by performing the confirmation experiments.