Papers by Keyword: Ultrasonic Cutting

Abstract: Ultrasonic cutting is a technique that can improve machinability such as fine surface, reduce tool worn out and etc. To improve processing speed of ultrasonic cutting is difficult due to the effects of tool oscillation are invalidated when cutting speed exceeds maximum tool oscillating velocity. In previous report, high speed principal direction ultrasonic turning experiments for stainless steel were carried out to improve processing speed and products quality. In ultrasonic turning, tool worn out and built up edge generation were reduced compare with ordinary turning. In this study, the effects of tool oscillating direction and tool chip shape for cutting properties of soft magnetic stainless steel were investigated. Cutting properties such as turned surface roughness, cutting force and ejected chip were compared.

Abstract: Automatic tape laying is a widely-used fabricating process for fiber-reinforced composite materials in aerospace and aviation industry. To fulfill the tape laying process, it is necessary to cut the prepreg tape into designated shape accurately and promptly. In this paper, a scheme of ultrasonic cutting bench is put forward to investigate the parameters of ultrasonic cutting process. The functional requirements are analyzed and the key components of ultrasonic cutting bench, such as transverse feed mechanism of cutter, revolving gear of cutter, and mechanism for precision positioning of cutting depth, are presented in detail, which lays a solid foundation for future experimental research.

Abstract: There are a number of problems with the traditional way of machining Nomex composite materials, Ultrasonic vibration cutting as a new method can overcome most of the problems. This paper presents the machining process characteristics of ultrasonic cutting honeycomb structures of Nomex composite materials using two kinds of specials tools, and has a research on Ultrasonic machining tools posture control strategy, then proposed calculation method of generating the cutter location date. The main system was developed to meet the automatic generation cutting path of Nomex composite materials based on VS2008 and UG commercial software. The result of experiment shows this system can automatic generate rational machining path and correct NC date.

Abstract: Ultrasonic cutting technique is an advanced processing method of cutting honeycomb materials. An ultrasonic pointed cutter was designed. Combined with the principle of ultrasonic cutting, the mathematical model of the tool was established. Modal analysis of the tool was calculated with the finite element software to study the effects of tool geometry on the natural frequency. The results show that the natural frequency increases as the tool thickness increases, but it decreases as the tool length increases. And it obtained the modal shapes and natural frequencies of the tool which meet design requirements. The optimal geometry of the tool was also determined. Finally, it verified the rationality of tool design by amplitude measurement experiment of the tool.

Abstract: The ultrasonic cutting of composite materials has the advantages such as high processing efficiency, high precision and non-pollution. The working principle of ultrasonic cutting is studied. The structure of circular tool is designed. The differential equation of tool frequency is established. The resonance frequency of tool is solved. Modal analysis is conducted for circular tool through ANSYS and the results are compared through tests.

Abstract: The impact of cutter against the materials can be regarded as the rigid ball with certain energy oblique impact against the semi infinite space in the ultrasonic vibration cutting process. The cutter and materials three-dimensional surface stress state was theoretically deduced from building the dynamic shock model in Hertz contact state. Ultrasonic vibration cutting in the tiny cutting depth can be regarded as the contact extrusion process of blunt pressure head oblique impact on materials, the material indentation and crack development trend was given based on the surface stress analysis and test results of rigid ball oblique impact on the glass. The indentation and crack development of spherical pressure head oblique impact on the brittle materials was analyzed, material failure in the back edge with deeper crack is controlled by tensile stress, the tensile stress values depend on the friction coefficient and the normal pressure, material failure crack caused by shear stress on both sides exist on the material surface. Ultrasonic vibration can reduce normal pressure and crack to come into being. Cutting fluid lubricating can reduce the friction coefficient to control with only shallow crack produced in the cutting process.

Abstract: The ultrasonic transmission model is established in the ultrasonic cutting process based on the ultrasound oval cutting device made by ourselves and the different vibration cutting effects is analyzed under the ultrasonic cutting process in this paper. The ultrasonic transmission at the contact interface is vulnerably affected by preload force factors and so on by the vibration experiments of the ultrasonic vibration cutting system.

Abstract: This study investigated phenomena of ultrasonic cutting in case of high speed conditions. Ultrasonically assisted cutting techniques were developed by Kumabe in 1950’s. He found “critical cutting speed” that limits cutting speed to obtain ultrasonically assisted effects and is calculated by frequency and amplitude of oscillation. In general, ultrasonically assisted cutting is not suitable for high speed cutting conditions because the effects of ultrasonically applying are canceled due to tool contacts with workpiece during cutting operation. Present ultrasonically assisted cutting cannot increase cutting speed because cutting speed is limited by above reason. And ultrasonically assisted cutting cannot improve productivity due to long processing time. We conducted high speed ultrasonic cutting, maximum cutting speed of this research was 160m/min which is higher than general critical cutting speed. Workpiece material is JIS SUS304 stainless steed and cemented carbide tool inserts were employed in this research. In ordinary cutting, generate terrible built up edge on to tool rake face. In case of low amplitude ultrasonic cutting, tool rake face hasn’t built up edge and periodically marks by ultrasonic oscillation were remained on the surface. Cutting phenomena of ultrasonic cutting is different compared with ordinary cutting conditions.

Abstract: This article introduced the Nomex honeycomb composite material, analyzed the insufficient of the traditional milling process in Nomex honeycomb composite processing, and proposed using the characteristics of ultrasonic cutting combined with NC technology to process the honeycomb composites. It analyzed the forming principle of the corresponding curved surface according to the special ultrasonic cutting tool and cutting method, and established a corresponding error.

Abstract: This study investigated phenomena of ultrasonic cutting in the case of high-speed conditions. Ultrasonically assisted cutting techniques were developed by Kumabe in the 1950s. He found a critical cutting speed that limits cutting speed to obtain ultrasonically assisted effects and is calculated by frequency and amplitude of oscillation. In general, ultrasonically assisted cutting is not suitable for high-speed cutting conditions because the effects of ultrasonic application are cancelled due to tool contacts with the workpiece during the cutting operation. Present ultrasonically assisted cutting cannot allow increased cutting speed because cutting speed is limited by a critical cutting speed that is less than that compared with general cutting speed. And ultrasonically assisted cutting cannot improve productivity due to long processing time. We conducted high-speed ultrasonic cutting, and the maximum cutting speed in this research was 300 m/min which is higher than general critical cutting speed. The workpiece material was A5056 and cemented carbide tool inserts were employed in this research. Without ultrasonic oscillation, machined surface retained some built up edge and surface roughness is 28 μmRz. In the case of ultrasonic cutting, surface hasnt built up edge and periodically marks due to ultrasonic oscillation remained on the surface. The roughness of conventionally cut surface is better than in ultrasonic cutting. The cutting phenomena of ultrasonic cutting are different compared with those under conventional cutting conditions.