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刘旭东李志永刘育辰柴明霞王永琪高存福 《制造技术与机床》2022,(11):45-51
为了研究光纤激光切割镍钛合金心血管支架过程中温度场分布情况,通过ANSYS有限元软件模拟建立了镍钛合金心血管支架三维仿真模型,运用APDL编程语言,实现高斯热源沿轨迹移动。采用单因素变量方法,探究激光功率、切割速度对不同切割轨迹温度分布以及变化的影响。结果表明,激光切割镍钛合金管时温度场分布近似为椭圆形,靠近热源中心处等温线分布较密集,远离热源中心等温线分布较稀疏。切割区域温度随激光功率的升高而增大,随切割速度的升高而降低。激光功率过大或切割速度过小时,会使熔渣在镍钛合金管内表面堆积严重。激光功率过小或切割速度过大时,会导致传递到管壁的热量不足,工件难以切透。仿真结果对实际切割参数的选取提供依据。 相似文献
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本文论述了通过开发M70数控系统的"工作数据读取功能",结合PLC程序的开发,使M70数控系统能够随时获得运行速度数据,实现了根据速度变化对激光功率的控制,从而避免了激光切割工件烧损的问题。这一技术对数控系统在激光切割机上的应用具有极大意义。 相似文献
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基于正交试验钛合金激光切割工艺参数优化 总被引:1,自引:0,他引:1
激光切割质量受各种因素的影响,为了得到高质量的激光切割件,需要根据不同的切割板材进行优化。利用厚度1.5mm的TC1薄板作为研究对象,研究激光功率、切割速度、焦点位置和辅助气体压力主要因素对激光切割质量的影响,采用正交试验方法安排激光切割试验,使用L16(45)正交表,完成十六组激光切割试验。利用测量点轮廓精度的算术平均值作为结果进行分析,采用直观分析法,因素效应曲线图,方差分析对切割参数进行分析研究。结果表明:切割速度和辅助气体压力是主要因素,对切割质量和精度有较大影响,而激光功率对切割后试件的轮廓度影响较之上两个因素小,但是激光功率改变对切割件的表面质量影响显著。 相似文献
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本文通过各项试验找出了各基本工艺参数对激光切割表面熔渣高度、表面粗糙度、切缝宽度、尖角熔损长度及热影响的影响规律性,可供从事激光切割工作人员参考。 相似文献
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为了揭示切割速度对6061铝合金薄板激光切割过程中温度场的分布及工艺规律,利用有限元软件对2 mm厚铝合金薄板在不同激光切割速度下的温度场进行数值模拟,并通过实验对仿真结果进行验证。仿真结果表明:当激光切割速度为80 mm/s时,工件的热影响区宽且熔深大,切缝处较宽范围内的材料均已达到熔点温度,随着切割速度增大,热影响区宽度、切缝处材料熔化量及熔深均逐渐减小。当切割速度为120 mm/s时,工件的熔深刚好达到材料的厚度。实验结果表明,当切割速度过低时,切缝处材料熔化量过多,在底部形成较厚的挂渣,随着切割速度增大切缝质量得到有效改善,但切割速度过大则会导致切缝处材料熔化量减小,粗糙度增大,切割速度为120 mm/s时,切缝质量最好。实验结果与仿真结果一致性较好,证明了仿真结果的准确性。 相似文献
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张鸿宾 《机械工人(热加工)》1985,(12)
一、激光切割的现象和原理激光切割是将激光束经透镜等集光系统得到高密度的光能,使被切割部位加热汽化,穿孔进行切割。现在的激光切割,一般都是与激光束同轴吹进气体,除极薄板的微细加工外,大多使用氧气或其它气体做辅助气体。利用气体辅助切割,对铁系材料来说有如下效果。1.氧气和铁的氧化反应热可以帮助加工部位的熔化;2.使生成的熔渣流动性好,并由气流将熔化 相似文献
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Saurabh Kajaria Sujeev Chittipolu Solomon Adera 《Machining Science and Technology》2013,17(4):524-546
This study investigates micromilling of 316 L stainless steel under minimum quantity lubrication. A laser-based technique was developed to measure spindle runout and assist tool setting for fragile micro cutting tools. Thresholds were established to help select cutting parameters and avoid catastrophic tool failure. Computational fluid dynamics was used to simulate flow of lubricant microdroplets around a rotating tool. When properly applied to wet the tool and workpiece, minimum quality lubrication reduces the build up edge on a cutting tool and increases the tool life up to 100 times compared to dry micromilling of 316L and stainless steel. 相似文献
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N. Tosun L. Ozler 《The International Journal of Advanced Manufacturing Technology》2004,23(11-12):777-782
This paper presents an investigation on the optimisation and the effect of cutting parameters on multiple performance characteristics (the tool life and the workpiece surface roughness) obtained by hot turning operations. A plan of experiments based on the Taguchi method was designed. M20 sintered carbide as tool and the high manganese steel as workpiece material were used in experiments. The workpiece material heated with liquid petroleum gas flame was machined under different settings of feed rate, depth of cut, cutting speed and workpiece temperature on a lathe. The results showed that cutting speed and feed rate were the dominant variables on multiple cutting performance characteristics. An optimum parameter combination was obtained by using statistical analysis. 相似文献
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The dynamics of a rotating Rayleigh beam subject to a force travelling at a constant speed along the axial direction is studied. The beam is chosen as a simple model of the workpiece in the lathing process. A technique is developed for modeling the repetitive cutting force on the workpiece. The amplitude of the cutting force is chosen to be either constant or dependent on the motion of the beam. The discretized equations of motion of the rotating beam are obtained by Galerkin’s method. The time response of the rotating beam subject to the external force is discussed. The possible resonant conditions resulting in divergent solutions are studied. The stability of the response, due to a travelling motion-dependent force, is determined by the method of multiple scales. The effects of varying the rotating frequency, the travelling speed of the external force, and the movement of the force are also investigated. 相似文献
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In laser beam machining with oxygen gas, striations are formed on the cut surface due to the cyclic oxidization reaction, which is affected by the cutting conditions and the thermal properties of the workpiece. The formation of striations causes an increase in surface roughness. In order to reduce the surface roughness, we propose controlling the formation of striations by utilizing multi-DOF oscillation of the focus position of the laser. In this paper, we construct a laser machining system in which positioning control of the focus position is achieved by driving the focal lens. The effect of orbital oscillation of the laser focus position parallel to the top surface of the workpiece and vertical oscillation perpendicular to this surface on the formation of striations was evaluated by performing laser cutting tests on thick mild steel plates. The experimental results show that control of the formation of striations can be realized by choosing the appropriate oscillation conditions. The surface roughness with oscillation was less than half that without oscillation. 相似文献
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Daniel Teixidor Joaquim Ciurana Ciro A. Rodriguez 《The International Journal of Advanced Manufacturing Technology》2014,71(9-12):1611-1621
The coronary stent fabrication requires a high-precision profile cut. Fibre lasers present a solution to accomplish these requirements. This paper presents an experimental study of fibre laser cutting of 316L stainless steel thin sheets. The effect of peak pulse power, pulse frequency and cutting speed on the cutting quality for fixed gas type and gas pressure was investigated. A mathematical model based on energy balances for the dross dimensions was formulated. The dross height and the dross diameter were analysed and compared with the experimental results. This allows adjustment of the process parameters to reduce the dimensions of the dross deposited at the bottom of the workpiece during laser cutting of thin sheets. 相似文献
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The dynamics of the workpiece of a lathe is simulated in the presented paper. A rotating Rayleigh beam is chosen as a simple model of the workpiece. The beam or the workpiece is subjected to forces from the cutting tool of the lathe. The external forces, in transverse and axial directions, are traveling in a repeating or periodic motion. The force in the axial direction is a large cutting force resulting in coupled bending deformation while forces in the transverse directions are the contacting forces.In this paper, the governing equations of the rotating Rayleigh beam are derived by Hamilton's principle. The external, periodic forces resulted from the tool are expressed in Fourier series. Galerkin's method is then chosen for disceretizing the partial differential equations. The instability regions of the responses are determined by using the method of multiple scales and the Floquet theory. Fast Fourier transform gives the frequency domain responses for examining the dynamic characteristics. The numerical results are discussed. Parametric studies are also performed. 相似文献
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S. Ranganathan T. Senthilvelan 《The International Journal of Advanced Manufacturing Technology》2011,56(5-8):455-462
This paper envisages the multi-response optimization of machining parameters in hot turning of stainless steel (type 316) based on Taguchi technique. The workpiece heated with liquid petroleum gas flame burned with oxygen was machined under different parameters, i.e., cutting speed, feed rate, depth of cut, and workpiece temperature on a conventional lathe. The effect of cutting speed, feed rate, depth of cut, and workpiece temperature on surface roughness, tool life, and metal removal rate have been optimized by conducting multi-response analysis. From the grey analysis, a grey relational grade is obtained and based on this value an optimum level of cutting parameters has been identified. Furthermore, using analysis of variance method, significant contributions of process parameters have been determined. Experimental results reveal that feed rate and cutting speed are the dominant variables on multiple performance analysis and can be further improved by the hot turning process. 相似文献
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《Wear》1987,116(3):309-317
Temperature rises in workpieces were measured during the cutting of various hardnesses of steel by a ceramic tool. Thermocouples were embedded in a specially designed workpiece for the temperature measurement. This workpiece provided practical and accurate positioning of the thermocouples and it allowed the acquisition of reliable data from the cutting experiments. The effects of the workpiece hardness and cutting speed were examined and analyzed. The relationships between the workpiece temperature rise and residual stresses or structural change in a machined surface layer were discussed.It is concluded that the temperature rise in a steel workpiece during cutting by a ceramic tool is so low that it is less likely to cause any surface damage under normal conditions. 相似文献