Papers by Keyword: Milling Process

Abstract: Accurate prediction of tool Remaining Useful Life (RUL) is essential for reliable and cost-effective milling, particularly when machining commercially pure titanium (CP-Ti), where tool wear is highly irregular. In industrial practice, continuously varying cutting conditions further complicate tool condition monitoring and life prediction. This paper proposes a vibration-based monitoring framework for RUL prediction under strongly variable milling conditions. A hybrid deep learning model based on CNN–BiLSTM is developed to capture the non-stationary relationship between vibration signals and tool degradation. Performance is compared between a spindle-mounted, non-invasive sensor and a tri-axial accelerometer mounted on the machine table, and the benefit of sensor fusion is assessed. Results show that spindle vibration correlates strongly with tool degradation and achieves predictive performance close to that of multi-sensor configurations, while requiring minimal instrumentation. The proposed approach remains robust under variations in both operating conditions and wear mechanisms, enabling reliable RUL estimation in non-stationary milling environments.

Abstract: Offline programming is a critical step in the implementation of various robotic tasks such as pick-and-place, welding, cutting, and milling. This paper describes a simulation study that analyses the accuracy of the robot's path tracking, during tasks that require the robot tool to interact with the environment, while considering the current operating conditions. To accurately determine the actual position of the Tool Center Point (TCP) and the associated orientation of the end effector, the study will first establish a robot model that takes into account the elasto-static behavior during the milling process that generates significant contact forces on the end effector. Then, an offline simulation tool is developed within the SolidWorks^® CAD environment. The analysis of simulation results from multiple scenarios revealed that the tool/material contact forces were the main source of the robot's deviation from its nominal trajectories. Moreover, the range of positioning errors varies according to the architecture of the robot and the workpiece emplacement. Depending on the working conditions, the tool deflection ranges from 0.1 mm to 0.75 mm in the or cutting directions and increases as one moves away from the reference frame, while the Cartesian orientation deviation is negligible (less than 1°).

Abstract: For machine design, determining the machine’s technical specifications as the basis for design element computation and choosing an appropriate electric motor are among the most crucial tasks. Especially, considering the scarcity of studies about tropical wood materials, it is more important to determine the specific work by the experimental approach. The scope of the study includes the research of dependency of the cutting power on the working parameters such as feed per tooth S_z, the cutting depth h, and the tooltip’s radius r in the process of wood material machining. Employing the response surface method, the experiments following the Central Composite Face design (FCCCD) plan were undertaken with 4 replicates. The author used Minitab software to process experimental results, analyze the regression equation and variance (ANOVA). In addition, the cutting force components in wood milling is also determined, which is the basis for the design of machine elements of wood milling machines and CNC woodworking machines.

Abstract: In order to study the milling process of compacted graphite iron cylinder block in practical, cutting parameters optimization experiment was conducted when cutting parameters were set as independent variable, and cutting efficiency and spindle power were set as optimization objective. The results showed that spindle power increased as the cutting speed and feed per tooth increasing, but cutting torque increased initially and then decreased as the cutting speed increasing. Feed force decreased with the increasing cutting speed and decreasing feed per teeth. Matlab software was used to optimize the cutting parameters when cutting efficiency and empirical formula of spindle power were settled as the objective functions. The most suitable parameters were abtained as V=164m/min and fz=0.28mm/z. The tool rake face mainly took place crater wear and material sticking. The main wear mechanisms for rake wear and fland wear were abrasive wear and adhesion wear.

Abstract: The micro-hardness and compression of recycling aluminum alloy AA6061 were investigated as a function of the different microstructure and constituent powder metallurgy method. Five specimens were selected to investigate the compression strength and microhardness. The first, as fabricated specimen (as compacted), the second was as heat treated by quenching and aging process. Three specimens were mixed with Graphite particles as a reinforcement material. Compression strength values were tested for the specimens as fabricated and heat treated which were 195 and 300 MPa, respectively. The improvement ratio was 52% for the specimen as heat treated. On the other hand, high wear resistance was given by the specimen as heat treated, whereas, the lower wear strength was at the specimen mixed with 4.5% Graphite. These results were attributed to that the wear resistance related to the microhardness value.

Abstract: Recently, as the automotive and aerospace industry research has focused one weight lightening, the use of functional aluminum alloys has been increasing. Aluminum alloys are effective materials because of their high specific strength and high stiffness ratio. However, machining deformation and heat deflection can occur depending on the machining type. Owing to these difficult-to-cut characteristics, it is necessary to monitor the machined surface quality of aluminum alloys. In this paper, we study the correlation between surface quality, namely burr formation and surface roughness, related to cutting parameters and signals obtained from multiple sensors. The output signals are measured by an acoustic emission (AE) sensor and an accelerometer and are analyzed in the signal frequency domain. By using the wavelet transform of analyzed signals, we determine the correlation between surface quality and signals. Based on this investigation, a surface quality monitoring system can be suggested.

Abstract: The micro-hardness and compression of recycling aluminum alloy AA6061 were investigated as a function of the different volume fraction and particle sizes by using powder metallurgy method. Three different groups of volume fraction and particle size were used 21.5, 50 and 78.5 % and 25,63 and 100 μm respectively. The current paper highlight on the effect of the various of particle size on the compression strength and microhardness results. The results of compression strength and micro-hardness show that the type of the higher amount of the smaller size was obtained for higher value for each of compression strength and micro-hardness 195.66 MPa and 79.796 Hv respectively.While it was the lower values on the type of the smaller amount of the smaller size (132.05 MPa and 50.369 Hv) respectively.

Abstract: In this paper, time domain simulation has been carried out to study the chatter stability of milling process. Dynamic chip thickness is calculated by analyzing the kinematics of the cutter, and thus dynamic governing equation revealing the dynamic behaviors between the cutter and workpiece is established. Solving framework is constructed by using the Simulink module and S-Function of Matlab software, and dynamic deflection is achieved with the four-order Runge-Kutta algorithm. With the simulated cutting forces, a criterion for the construction of the stability lobe is suggested. At the same time, algorithm for the prediction of the surface topography involving the dynamic response of the machining system is developed.

Abstract: The objective of this paper is to analyze the precision of plastic parts made by using robot milling. Currently, the robots have good precision, rigidity, flexibility and they are able to machine parts. By using a six axis Kuka robot and an electric spindle, a plastic part was milled. The paper presents the advantages and disadvantages of this new technology, analyzing the dimensional accuracy, surface quality and costs.

Abstract: The existing processes of controlling machining error just controlled the maximum error. However, it did not effectively control the distribution of the error.The reliability of the assembly precision of the key joint surface did not meet the requirements, thereby affecting the service performance of machine tool. To solve this problem, the error matrix and transformation matrix was used to ascertain the location of joint surface positioning error occurred. The influence of processing error on the the positioning accuracy of machine tool was analyzed. The control objective of milling process was proposed. At the same time, the effects of cutting parameters on the processing error were also studied according to the milling experiments. The process error and its distribution characteristics of joint surface were obtained by analyzing the relationship between deformation of joint surface and cutting parameters. The milling process control methods were proposed.