Fabrication of Multiple Micro-Grooves by Ultrasonic Machining with a Tool that Laminated Thin Hard-Material and Thin Soft-Material

2009 ◽  
Vol 76-78 ◽  
pp. 577-582 ◽  
Author(s):  
Jun Shinozuka

A micro-grooving method by ultrasonic machining with a lamination tool has been devised. Thin walls on the tip of an ultrasonic tool can fabricate many grooves on a workpiece by one ultrasonic-machining process. Thinner wall for fabricating micro grooves, however, poses the lack of the stiffness of the tool, resulting in the difficulty of the grooving. Then the walls are enfolded with a soft material such as a polymer plastic to supplement the lack of the stiffness. Since soft material absorbs the energy of the ultrasonic vibration, the damage by the impacts of the abrasive particle on the workpiece surface under the soft material is little. Therefore multiple micro-grooves can fabricate efficiently by using of a lamination tool in which thin hard-materials and thin soft-materials are laminated alternately. In this paper, the lamination tools were developed with a thin shim-sheet as the hard material and an epoxy adhesive as the soft material. The fabrication experiments of the parallel grooves on alumina ceramics were conducted. This paper investigates the influences of the parameters of ultrasonic machining such as the grain size of the abrasive particle, the static machining load or static normal stress applied to the tool-workpiece contact region and the grooving time upon the characteristics of the micro-grooves. The results show that the grooving efficiency depends on the grooving time and the static normal stress. Finally, some applications are shown.

Author(s):  
Eliad Cohen ◽  
Vishesh Vikas ◽  
Barry Trimmer ◽  
Stephen McCarthy

Soft material robots have gained interest in recent years due to the mechanical potential of non-rigid materials and technological development in the additive manufacturing (3D printing) techniques. The incorporation of soft materials provides robots with potential for locomotion in unstructured environments due to the conformability and deformability properties of the structure. Current additive manufacturing techniques allow multimaterial printing which can be utilized to build soft bodied robots with rigid-material inclusions/features in a single process, single batch (low manufacturing volumes) thus saving on both design prototype time and need for complex tools to allow multimaterial manufacturing. However, design and manufacturing of such deformable robots needs to be analyzed and formalized using state of the art tools. This work conceptualizes methodology for motor-tendon actuated soft-bodied robots capable of locomotion. The methodology relies on additive manufacturing as both a prototyping tool and a primary manufacturing tool and is categorized into body design & development, actuation and control design. This methodology is applied to design a soft caterpillar-like biomimetic robot with soft deformable body, motor-tendon actuators which utilizes finite contact points to effect locomotion. The versatility of additive manufacturing is evident in the complex designs that are possible when implementing unique actuation techniques contained in a soft body robot (Modulus discrepancy); For the given motor-tendon actuation, the hard tendons are embedded inside the soft material body which acts as both a structure and an actuator. Furthermore, the modular design of soft/hard component coupling is only possible due to this manufacturing technique and often eliminates the need for joining and fasteners. The multi-materials are also used effectively to manipulate friction by utilizing soft/hard material frictional interaction disparity.


Author(s):  
Chittaranjan Sahay ◽  
Suhash Ghosh ◽  
Hari Kiran Kammila

Proper selection of manufacturing conditions is one of the most important aspects in Ultrasonic Machining process, as these conditions determine the Material Removal Rate (MRR). In this work, two very popular mathematical models proposed by Miller and Shaw have been investigated using Monte Carlo simulation based Crystal Ball analysis tool. Effects of abrasive particle size, particle concentration, amplitude of tool vibration, tool radius and depth of hole on MRR have been analyzed for both models. Miller’s model indicates a strong positive relationship between abrasive grain size, concentration and MRR. Contrary to the literature search on experimental data, Shaw’s mathematical model indicates a negative relationship between MRR and grain size, and a very weak relationship between MRR and concentration. No definite relationship could be established between either tool radius and MRR or amplitude and MRR. A negative relationship between depth of hole and MRR was obtained for Shaw’s model.


Author(s):  
Z. Yu ◽  
X. Hu ◽  
K. P. Rajurkar

As a micro mechanical machining process, micro ultrasonic machining (micro USM) has the major advantage of producing micro-scale components or features in brittle (glass, quartz crystal, and sapphire) and hard (ceramics) materials. Micro USM is used to generate micro holes with 5μm in diameter and 3D micro cavities. However, the relationship of machining parameters such as static load, abrasive particle and amplitude of vibration and the material removal rate is not clearly understood. In this paper, a mathematical model is developed to describe the material removal process in micro USM. Experiments were carried out to verify the model. It was found that the machining speed decreases when the load is over a certain value, which is different from that of theoretical model. To understand this phenomenon, a simple model was proposed to analyze it qualitatively. It was found that the debris accumulation around the crater in a short time is the main reason resulting in the low machining efficiency.


2016 ◽  
Vol 693 ◽  
pp. 837-842
Author(s):  
Fu Yi Xia ◽  
Li Ming Xu ◽  
De Jin Hu

A novel principle of cup wheel grinding of rotating concave quadric surface was proposed. The mathematical model of machining process was established to prove the feasibility of precision grinding of rotating concave paraboloid based on the introduced principle. The conditions of non-interference grinding of concave paraboloid were mathematically derived. The processing range and its influence factors were discussed. The trajectory equation of abrasive particle was concluded. Finally, the math expressions of numerical controlled parameters was put forward in the process of grinding of the concave paraboloid.


2010 ◽  
Vol 443 ◽  
pp. 645-651 ◽  
Author(s):  
Alireza Moridi ◽  
Jun Wang ◽  
Yasser M. Ali ◽  
Philip Mathew ◽  
Xiao Ping Li

Owing to its various distinct advantages over the other machining technologies, abrasive jet machining has become a promising machining technology for brittle and hard-to-machine materials. An experimental study is presented on the micro-grooving of quartz crystals using an abrasive airjet. The effect of the various process parameters on the major machining performance measures are analysed to provide a deep understanding of this micro-machining process. Predictive models are then developed for quantitatively estimating the machining performance. The models are finally verified by an experiment. It shows that the model predictions are in good agreement with the experimental results under the corresponding conditions.


Author(s):  
Pradeep L. Menezes ◽  
Kishore ◽  
Satish V. Kailas

Surface texture plays an important role as it predominantly controls the frictional behavior and transfer layer formation at the contacting surfaces. In the present investigation, basic studies were conducted using inclined pin-on-plate sliding tester to understand the role of surface texture of hard material on coefficient of friction and transfer layer formation when sliding against soft materials. HCP materials such as pure Mg and pure Zn were used as pins while 080 M40 steel was used as plate in the tests. Two surface parameters of steel plates — roughness and texture — were varied in the tests. Tests were conducted in ambient conditions under both dry and lubricated conditions. The morphologies of the worn surfaces of the pins and the formation of transfer layer on the counter surfaces were observed using a scanning electron microscope. It was observed for both the pin materials that the occurrence of stick-slip motion, the transfer layer formation and the value of coefficient of friction as well as its two components, namely, adhesion and plowing, depend primarily on surface texture. The effect of surface texture on coefficient of friction was attributed to the variation of plowing component of friction for different surfaces. Both the plowing component of friction and amplitude of stick-slip motion were highest for the surface texture that promotes plane strain conditions while these were lowest for the texture that favors plane stress conditions at the interface.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1405
Author(s):  
Jian-Guo Zhang ◽  
Zhi-Li Long ◽  
Wen-Ju Ma ◽  
Guang-Hao Hu ◽  
Yang-Min Li

Ultrasonic transducer is a piezoelectric actuator that converts AC electrical energy into ultrasonic mechanical vibration to accelerate the material removal rate of workpiece in rotary ultrasonic machining (RUM). In this study, an impedance model of the ultrasonic transducer is established by the electromechanical equivalent approach. The impedance model not only facilitates the structure design of the ultrasonic transducer, but also predicts the effects of different mechanical structural dimensions on the impedance characteristics of the ultrasonic transducer. Moreover, the effects of extension length of the machining tool and the tightening torque of the clamping nut on the impedance characteristics of the ultrasonic transducer are investigated. Finally, through experimental analysis, the impedance transfer function with external force is established to analyze the dynamic characteristics of machining process.


Sign in / Sign up

Export Citation Format

Share Document