bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of High-Performance Polycrystalline CVD Diamond Coated Cutting Tool Edge With Femtosecond Laser
Authors: Liu Xiaoxu , Natsume Kohei , Maegawa Satoru , Itoigawa Fumihiro 
Published: January 2021

Abstract
To realize the high performance of CVD diamond coated tools, a tool edge shaping process named pulse laser grinding (PLG) was developed with short pulse laser in our group previously. In this study, femtosecond laser was innovatively to be used to conduct the PLG process, since femtosecond laser is famous for its less thermal impact and some newly reported surface modification effect. The results show that PLG processing under high laser fluence of femtosecond laser could achieve roundness around 1 μm, which is similar to that of conventional PLG process with nanosecond laser, although the roughness of processed surface has been worse due to the redeposited debris. Furthermore, an interesting phenomenon has been confirmed again that under low laser fluence irradiation of femtosecond laser, the CVD diamond surface shows improved crystallinity of diamond structure. Based on this, a two-step tool edge processing method was proposed, which could realize the edge shaping and surface modification together with one laser processor. And the results show that the processed tool edge with much less edge roundness and surface roughness, and the tip part with better diamond crystallinity, indicating that sharper and hardness tool edge could be possibly to be realized with femtosecond laser.
Chatter Stability Prediction of Cutting Process With Process Damping Utilizing Finite Element Analysis
Authors: Suzuki Norikazu , Nakanomiya Tomoki , Shamoto Eiji 
Published: January 2021

Abstract
This paper presents a new approach to predict chatter stability in cutting considering process damping. Traditional chatter stability analysis methods enable to predict stable or unstable conditions. Under unstable conditions, the chatter vibration can increase theoretically infinitely. However, chatter vibration is damped at a certain amplitude in real process due to process damping, i.e., the cutting process is stabilized by means of tool flank face contact to the machined surface. In order to consider the influence of the process damping, a simple process damping force model is introduced. The process damping force is assumed to be proportional to the structural displacement. The process damping coefficient is a function of the vibration amplitude and the wavelength. In order to identify the coefficients, a series of finite element analysis is conducted in the present study. Identified coefficients are introduced into the conventional zero-order-solution in frequency domain. The proposed model calculates chatter stability limit assuming process damping with finite amplitude. Hence, this analysis enables to estimate the amplitude-dependent quasi-stable conditions. Analytical results for thee face turning operation demonstrated influence of process damping effect on resultant vibration amplitude quantitatively.
Effect of Cutting Temperature on Phase Transformation in Cutting of NiTi Alloy
Authors: Yang Hao , Sakai Katsuhiko , Shizuka Hiroo , Hayakawa Kunio , Nagare Tetsuo 
Published: January 2021

Abstract
In this study, the effect of cutting temperature on phase transformation in cutting of room temperature austenitic NiTi alloy was investigated by X-ray diffraction (XRD) and temperature measurements. Results from XRD reveals that after cutting process, the phase state of work material near the machined surface transformed from austenite to martensite at relatively low cutting speed conditions while the phase state of work material did not undergo any form of transformation at the highest cutting speed condition. Temperature measurement results measured with temperature indicating paint showed that the maximum temperature of work material near the machined surface in cutting process exceeded the Md temperature at the highest cutting speed condition. However, there was no phase transformation observed in cutting chips after cutting at all cutting speed conditions as the temperature of cutting chips was much higher than the Md temperature under all cutting speed conditions.
Control of Material Flow During Friction Stir Welding Between Aluminum and Steel by Welding Tool Shape
Authors: Yasui Toshiaki , Ogura Yuki , Huilin Xu , Najwa F. Farrah , Sugimoto Daichi , Ito Atsushi , Fukumoto Masahiro 
Published: January 2021

Abstract
For the Friction stir welding (FSW) between aluminum and steel is important to fabricate vehicles with light weight and high strength for safety at low cost. For the fabrication of sound weld, it is necessary to control the material flow during FSW. In this study, the material flow during FSW was elucidated by numerical simulation by computational fluid dynamics (CFD) analysis and simulation experiment by transparent Poly-vinyle chloride (PVC) as simulant of aluminum and tracer material. Based on this material flow analysis, several shapes of welding tool were examined for control of material flow during FSW. Scroll shoulder is effective for enhancement of stirring zone by increasing material velocity around the probe. Flute and fine screw probe promote the material flow in depth and horizontal direction. The welding tool with scroll shoulder and flute and fine screw probe achieved sound weld with highest tensile strength of 120.4 MPa.
Improvement of the Form Accuracy Ground by a Slender Wheel in Internal Grinding
Authors: Onishi Takashi , Nakabayashi Yusuke , Sakakura Moriaki , Ichiba Go , Ohashi Kazuhito 
Published: January 2021

Abstract
In the case of internal grinding of a deep hole, the inner surface of the hole was ground by a slender grinding wheel that has a high aspect ratio. A slender grinding wheel is bent by the normal grinding force during the grinding process. Therefore, the form accuracy of the ground workpiece is decreased especially when the aspect ratio of a wheel is high. In our previous study, it was confirmed that the biggest factor that generated the form error of the workpiece was the elastic deformation owning to the normal grinding force. To reduce the form error of the ground workpiece, it is effective to expand the spark-out duration. However, the expansion of the spark-out duration leads to the low productivity. In this study, the form of the grinding wheel was modified by a diamond dresser to improve the form accuracy of the workpiece without expanding the spark-out duration. The modified form of a wheel was determined to compensate the form error of the workpiece generated by the elastic deformation of the grinding wheel. Thorough several grinding experiment, it was confirmed that the form accuracy of the ground workpiece was successfully improved by modifying the form of a slender grinding wheel without expanding the spark-out duration.
Thin Film Stress Sensor on the Tool Rake Face for Orthogonal Cutting
Authors: Obikawa Toshiyuki , Yagi Kenji , Hayashi Mamoru 
Published: January 2021

Abstract
The evaluation of stress and temperature on the tool faces during machining is very important for understanding the fundamental mechanism of machining processes, developing cutting tools, optimizing cutting conditions. Although cutting temperature has been often measured using the tool-chip thermocouple method, a two-color pyrometer, etc., measurement of stress on the tool face has been hardly reported. For this reason, a cutting tool with a thin film stress sensor in the surface layer of the rake face was developed for orthogonal cutting. The film sensor was made of manganin, a copper-manganese-nickel alloy having piezoresistance effect. The manganin was coated on the rake face of polished silicon nitride matrix by magnetron sputtering in a specific pattern having a line 30 micrometer wide and 0.2 micrometer thick along the cutting edge. Then, the rake face was further coated with silicon nitride for protecting the thin stress sensor. After the calibration of the sensor, the tool was applied to orthogonal cutting experiment, in which MC Nylon and polyvinyl chloride were machined at a very low cutting speed. For four levels of uncut chip thickness from 0.05 to 0.20 mm the stress was measured for MC Nylon. The measured stress seems consistent with stress distributions measured by photoelasticity method reported so far.
Robustness of Detection Method for Clamp Force Against Configuration Error in Bolt/Nut Assemblies
Authors: Hashimura Shinji , Kubota Kai , Ohmi Nozomu , Komatsu Kyoichi 
Published: January 2021

Abstract
Reliability of bolt/nut assemblies directly influences the quality of machines and structures. It is most important to control and maintain the clamp force of bolt/nut assemblies to secure reliability. However it is not easy to control the clamp force during tightening. And it is also difficult to detect the clamp force after tightening. In our previous study, we proposed a method to easily detect the clamp force of bolt/nut assemblies that have already been tightened. In the method, the bolt thread portion protruding from the nut is pulled while supporting the nut’s upper surface. The relationship between the tensile force and the displacement at the pulling point differs before and after the tensile force reaches the clamp force. The method can detect the tensile force at the point where the relationship changes as the clamp force.
In this study, robustness of the detection method for the squareness error of the bearing surface of clamped parts has been investigated by FE analysis and experiments. The results of the FE analysis showed that the squareness error of the bolt bearing surface does not have an influence on the detection accuracy. The results indicate that the detection method has robustness for the squareness error of bolt bearing surfaces. Contrary to that, the experimental results show that the squareness error does have a clear influence on the detection accuracy. The averages of detection error in the experiments increased about 10% with an increase in squareness error. It is considered that the error was caused because the mating thread surfaces did not separate when the tensile force reached the clamp force.
A Reconfigurable Jig Assistant Assembly System Based on Wearable Devices
Authors: Qin Zhaojun , Lu Yuqian , Zhang Hongbo , Liu Xinyu , Zheng Lianyu 
Published: January 2021

Abstract
In the aviation industry, the novel reconfigurable jig has a good application prospect. However, compared with traditional fixed jigs, the flexible structure of reconfigurable jig increases the assembly difficulty, as well as the disadvantage of cooperation between devices. To cope with these problems, we propose a reconfigurable jig assistant assembly (RJAA) system based on wearable devices in this paper, which can enhance the collaboration between humans and machines, and improve the automation level of assembly operations. Firstly, the architecture of the RJAA system is presented, which is composed of three units, i.e. server application unit, wearable application unit, and assembly execution/auxiliary unit. Secondly, in order to achieve the collaboration within the RJAA system, a unified message cooperation communication protocol is designed. Finally, we tested the developed system on the assembly of a 6-UPS parallel mechanism to validate the effectiveness and feasibility of the proposed system.
Effect of Hatch Angle Rotation on the Thermal and Mechanical Properties of Micro Selective Laser Melted NiTi Shape Memory Alloy
Authors: Fu Jin , Hu Zhiheng , Song Xu , Fu Mingwang 
Published: January 2021

Abstract
NiTi shape memory alloy (SMA) has been widely used for bio-medical and aerospace applications due to its unique properties, i.e. shape memory effect and pseudoelasticity. However, the high ductility and work-hardening effect of NiTi lead to poor machinability. Additive manufacturing (AM), with excellent capability of fabricating complicated structures, has been used to fabricate NiTi components. To meet the increasing demand of product miniaturization, micro selective laser melting (μSLM) system equipped with finer laser beam has been developed to improve manufacturing resolution. This work studies the fabrication of NiTi SMA parts by μSLM for the first time. The effect of hatch angle rotation on the thermal and mechanical behaviors of μSLMed NiTi is analyzed. Columnar grains accompanied with equiaxed grains are observed in μSLMed NiTi. Laser rotation angles of 45/60/90° lead to weak crystallographic texture. Ti-rich secondary phases including Ti2Ni/Ti4Ni2Ox and TiC1-xNx are detected in the raw NiTi powder and the as-printed NiTi parts, respectively. The as-printed parts under different hatch angles show similar phase constitution. The thermal-induced transformation behavior was depressed with absence of transformation peak. The variation of hatch angle cannot activate the transformation peak. Varying hatch angle from 45° to 90°, the compressive strength and ductility reduce, and the hardness increases. The depressed thermal-/stress-induced phase transformation of the μSLM NiTi can be attributed to the Ti-rich secondary phases, which cause variation of matrix Ni/Ti ratio and inhomogeneous microstructure.
Thermal Stress Simulation Model of Dissimilar Linear Friction Welding (LFW) Technology for Manufacturing of Bi-Metallic Biomedical Implants
Authors: Glaspell Aspen , Seydlorsky Christina , Son Junbeom , Ryu Jae Joong , Choo Kyosung 
Published: January 2021

Abstract
Linear Friction Welding (LFW) is a uniquely important manufacturing process because it allows welding of dissimilar materials without filler material. In this study, bi-metallic Ti6Al4V-CoCrMo joints were manufactured using LFW process and analyzed the weldability and bonding strength. Ti6Al4V and CoCrMo cylinders were manufactured to a standard size of tensile specimens and cut into two identical pieces. The surfaces to be welded were polished and cleaned before performing welding. The experimental thermal data was recorded with an IR camera.
In the thermal stress simulation model, the temperature-dependent thermal properties of Ti-6al-4V were used. The thermal properties of CoCrMo were assumed constant due the fact that CoCrMo does not change phase until it reaches its melting temperature. The heat losses due to radiation was different for each workpiece because both materials had a different emissivity and the heat loss by convection is a function of the surface temperature by natural convection. The left boundary of the Ti-6Al-4V and the right boundary of the Co-Cr-Mo workpiece were constrained at a constant temperature of 45°C. The maximum deformation of the simulation model is well matched with the measured data within 5% error.
Experimental Investigation of the Machinability of Single Crystal Silicon in Laser-Assisted Diamond Cutting
Authors: Ke Jinyang , Chen Xiao , Zhang Jianguo , Liu Changlin , Xu Guoqing , Chu Jianning , Xiao Junfeng , Xu Jianfeng 
Published: January 2021

Abstract
Laser-assisted diamond cutting is a promising process for machining hard and brittle materials. A deep knowledge of material removal mechanism and attainable surface integrity are crucial to the development of this new technique. This paper focuses on the application of laser-assisted diamond cutting to single crystal silicon to investigate key characteristics of this process. The influence of laser power on the ductile machinability of single crystal silicon, in terms of the critical depth of cut for ductile-brittle transition in laser-assisted diamond cutting, is investigated quantitatively using a plunge-cut method. The experimental results reveal that this process can enhance the silicon’s ductility and machinability. The critical depth of cut has been increased by up to 330% with laser assistance, and its degree generally increases with the increase of laser power. The cross-sectional transmission electron microscope observation results indicate that laser-assisted diamond cutting is able to realize the subsurface damage free processing of single crystal silicon. In order to verify the ability of the laser-assisted diamond cutting to improve the surface quality, the face turning tests are also carried out. A significant improvement of surface quality has been obtained by laser-assisted diamond cutting: Sz (maximum height) has been reduced by 85% and Sa (arithmetical mean height) has been reduced by 45%.
Research on Intelligent Optimization Algorithm for Multi-Objective Disassembly Line Balancing Problem
Authors: Xu Yunli , Yao Bitao , Pham Duc Truong 
Published: January 2021

Abstract
For resource reutilization and environmental protection, remanufacturing gets more and more attention in many countries. Disassembly is a critical part of traditional manufacturing industry, but the traditional disassembly operation is mainly done by workers, which is low-efficiency. Now the use of robots can improve production efficiency a lot, which involves the problem of disassembly line balancing. Due to the constraints such as product complexity and precedence relationship between tasks, when the number of tasks increases, the combination scheme between tasks increases geometrically, and conventional algorithms are difficult to solve the problems, the Disassembly Line Balancing Problem (DLBP) is generally necessary to optimize multiple objectives. In this research, the author selects a variety of intelligent optimization algorithms to resolve the complex disassembly line balancing problem in different dimensional objective space. Four representative algorithms are selected from three angles to be compared through three performance indicators. It is concluded that these algorithms have different search capabilities for different specifications and objective space. Researchers should carefully select the algorithm according to the specific disassembly problem. The appropriate algorithm should be selected according to the scale of the disassembly line problem and the number of optimization objectives in actual production practice.
Study on the Thermal Expansion Effects of the 3D Printed Space Instrument
Authors: Fursova Anastasiia , Konev Stepan , Velasquez-García Luis , Sun Zhumei , Nikolaev Evgeny 
Published: January 2021

Abstract
Space is one of the most mysterious and unexplored places for humanity. It has a dangerous environment that critically affects everything that is launched there. In this case, an enormous challenge for engineers now is to find cheap but effective manufacturing methods that can provide an instrument that is stable during launch, landing, and work time of the mission. Additive technologies are a credible method for this task. It can provide materials that are stable in the big range of temperature, vacuum, and stresses.
Unfortunately, some of the instruments need high precision of the surfaces that could be damaged during the mission. The mass spectrometer is one of such devices. One of its main parts is the ion trap that extremely sensitive to a displacement of the surface. Our perspective mission is on Moon Polar Caps, where extreme temperatures are. Thermal compression could crucially change surface profile and decrease the quality of the mass spectrometry measurements.
The goal of the research is to conduct a thermomechanical analysis of the 3D printed metal Kingdon ion trap, for the conditions of the Moon surface. At this point, we have created the prototype by inkjet printing techno logy, performed thermal expansion analysis and tests.
Results show that the thermal expansion could significantly affect the performance of the instrument. We are proposing to introduce corrections to the shape of the surface.
A Novel Real-Time Thermal Analysis and Layer Time Control Framework for Large Scale Additive Manufacturing
Authors: Fathizadan Sepehr , Ju Feng , Rowe Kyle , Fiechter Alex , Hofmann Nils 
Published: January 2021

Abstract
Production efficiency and product quality need to be addressed simultaneously to ensure the reliability of large scale additive manufacturing. Specifically, print surface temperature plays a critical role in determining the quality characteristics of the product. Moreover, heat transfer via conduction as a result of spatial correlation between locations on the surface of large and complex geometries necessitates the employment of more robust methodologies to extract and monitor the data. In this paper, we propose a framework for real-time data extraction from thermal images as well as a novel method for controlling layer time during the printing process. A FLIR™ thermal camera captures and stores the stream of images from the print surface temperature while the Thermwood Large Scale Additive Manufacturing (LSAM™) machine is printing components. A set of digital image processing tasks were performed to extract the thermal data. Separate regression models based on real-time thermal imaging data are built on each location on the surface to predict the associated temperatures. Subsequently, a control method is proposed to find the best time for printing the next layer given the predictions. Finally, several scenarios based on the cooling dynamics of surface structure were defined and analyzed, and the results were compared to the current fixed layer time policy. It was concluded that the proposed method can significantly increase the efficiency by reducing the overall printing time while preserving the quality.
Finite Element Method (FEM) Based Simulation of Continuous Laser Ablation: Surface Temperature and Depth Profile Evolution
Authors: Ravi-Kumar Sandeep , Jiang Liangkui , Qin Hantang 
Published: January 2021

Abstract
Laser ablation has been widely used for material removal on different types of substrates. Accurate feature profile fabrication with minimum damage to the surrounding material requires precise control of the laser and material parameters. One approach to achieve this is by establishing a simulation model to help process control and optimization. However, laser ablation is a complex process that is difficult to model. In this paper, numerical simulation models have been established to identify the temperature at the ablation surface and the ablation depth profile evolution over time. The ablation has been modeled using the heat transfer in solids module in COMSOL Multiphysics with the manual material definition of high-density polyethylene (HDPE). The laser beam is modeled as a continuous heat source by utilizing a ramp function. Information for establishing a pulsed laser system has been provided. Results are provided for the surface temperature and depth profile evolution for various time steps. Results of the simulation of laser ablation of HDPE sample using a 50W laser using both the models were presented. The next step of our work is to validate the simulation results by comparing it against experimental data. This will render these models to have the potential to be able to predict the ablation crater profile with higher accuracy. This model will pave the way for a better understanding of the ablation threshold conditions and identifying the ablation initiation in any material, given the material properties are known.