In the internal thread extrusion forming, if the process parameters are not selected properly, the extrusion torque will increase, the extrusion temperature will be too high, or even the tap will break. In order to obtain effective process parameters under certain working conditions, this paper uses a combination of numerical simulation and process experiment to analyze the influence of the bottom hole diameter, extrusion speed, and friction factor on the extrusion torque and extrusion temperature. Through an orthogonal experiment, the significant influence law of different process parameters on the extrusion torque and extrusion temperature was studied, and the order of their influence was determined. Based on the optimal process parameters, numerical simulations and process tests were carried out, and the extrusion effect and related parameters were compared and analyzed. The results show that the extruded thread has clear contour, uniform tooth pitch, complete tooth shape, and good flatness. Compared with before optimization, the maximum extrusion torque has been reduced by 37.15%, the maximum temperature has been reduced by 29.72%, and the extrusion quality has been improved. It shows that the optimized method and optimized process parameters have good engineering practicability.
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http://dx.doi.org/10.3390/ma13183960 | DOI Listing |
J Phys Chem A
January 2025
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
When dielectrics are hit with intense infrared (IR) laser pulses, transient metalization can occur. The initial attosecond dynamics behind this metallization are not entirely understood. Therefore, simulations are needed to understand this process and to help interpret experimental observations of it, such as with attosecond transient absorption (ATA).
View Article and Find Full Text PDFTissue Eng Regen Med
January 2025
Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361102, Fujian, China.
Background: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time.
Methods: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed.
J Mol Model
January 2025
School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Haidian District, Ding No.11 Xueyuan Road, Beijing, 100083, People's Republic of China.
Context: Understanding the structural characteristics of coal at the molecular level is fundamental for its effective utilization. To explore the molecular structure characteristic, the long-flame coal from Daliuta (DLT), coking coal from Yaoqiao (YQ), and anthracite from Taixi (TX) were investigated using various techniques such as elemental analysis, Fourier transform infrared spectroscopy, solid-state C nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy. Based on the structural parameters, the coal molecular model was constructed and optimized.
View Article and Find Full Text PDFTraffic Inj Prev
January 2025
School of Intelligent Transportation and Engineering, Guangzhou Maritime University, Guangzhou, China.
Objective: The objective of this study was to assess drivers' visual search patterns and cognitive load during driving in curved tunnels. Specifically, we aimed to investigate how different curved tunnel geometries (tunnel radii, turning directions) and zones (entrance, middle, exit) influence drivers' saccadic eye movements. This understanding can inform the development of safer tunnel designs and driving guidelines.
View Article and Find Full Text PDFLangmuir
January 2025
Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China.
Self-cleaning applications based on bionic surface designs requires an in-depth understanding of unique and complex wetting and evaporation processes of sessile droplets on natural biosurfaces. To this end, hydrophobic bamboo and Kalanchoe blossfeldiana leaves are excellent candidates for self-cleaning applications, but various properties, such as the heat and mass transfer processes during evaporation, remain unknown. Here, the dynamics of contact angle, radius, and heat and mass transfer during evaporation of sessile droplets on bamboo and Kalanchoe blossfeldiana leaves with roughness in the range 2.
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