Precision Machining Technology Research Articles

Phase calculation of smooth surface with multi-reflectivity based on phase measurement deflectometry

With the continuous advancement of precision machining technology and the growing demand for products, increasingly complex objects with high reflectivity are becoming more prevalent in production and daily life. phase measurement deflectometry (PMD) is a technique that utilizes a surface light source to project structured light for comprehensive detection of highly reflective surfaces. It offers advantages such as high accuracy, fast speed, low cost, and non-contact operation. However, when the surface of the object being measured has varying levels of reflectivity, this method may produce errors due to significant differences in fringe contrast between different reflective areas. In order to enable the fringe deflection system to simultaneously detect multiple reflective objects without sacrificing accuracy, this paper proposes an adaptive method for fringe generation detection. This method can adaptively adjust the intensity based on the reflectivity of the measured surface and compensate for the light at the reflectivity boundary, ultimately achieving phase calculation for multiple reflective surfaces.

Theoretical and experimental investigations on conformal polishing of microstructured surfaces

Microstructured surfaces play a pivotal role in various fields, notably in lighting, diffuser devices, and imaging systems. The performance of these components is intricately related to the accuracy of their shapes and the quality of their surfaces. Although current precision machining technologies are capable of achieving conformal shapes, the post-machining surface quality often remains uncertain. To appropriately address this challenge, this paper introduces a novel conformal polishing methodology, specifically designed to enhance the surface quality of microstructured surfaces while maintaining their shape accuracy. As part of the investigations, specialized tools, namely the damping tool and profiling damping tool, are methodically developed for polishing rectangular and cylindrical surfaces. A shape evolution model is established based on the simulation of individual microstructures, incorporating the concept of finite-slip on the microstructured surface. The findings reveal that principal stresses and velocities experience abrupt variations at the convex and concave corners of rectangular surfaces as well as at the ends of cylindrical surfaces. The numerically predicted surface shape errors after polishing demonstrate reasonably good agreement with experimental results such that their discrepancies are less than 1 μm. Additionally, this method is able to successfully eradicate pre-machining imperfections such as residual tool marks and burrs on the microstructured surfaces. The arithmetic roughness (Ra) of the rectangular surface is measured to be an impressively low 0.4 nm, whereas the cylindrical surface exhibits Ra = 6.2 nm. These results clearly emphasize the effectiveness of the conformal polishing method in achieving high-quality surface finishes.

Fluid dynamics simulation on water lubricating performance of micro-/nano-textured surfaces considering roughness structures

With the development of surface precision machining technology and extensive studies on lubrication and friction reduction, the use of surface texture to reduce friction has attracted widespread attention, but few studies have considered the influence of surface roughness on lubrication characteristics. By employing the computational fluid dynamics (CFD) simulation method, the lubrication models with rectangular textures and the introduction of rough asperity structures at the same time are established. The effects of the corresponding structure parameters on the lubrication performance of textured and roughed surfaces are studied under water lubrication conditions. Our results suggest that the adjustment of geometric parameters on the micro-/nano-structured surfaces can influence the load-bearing capacity of the water lubrication film, thus affecting the hydrodynamic lubrication performance on the surface. In addition, the generation of vortex in the micro-textures can bring changes in vorticity, which causes energy dissipation and affects frictional forces. In the lubrication model with rectangular textures, optimal hydrodynamic lubrication performance is obtained under the appropriate depth ratio <i>H</i> = 0.6. Meanwhile, the corresponding lubrication performance can be enhanced by increasing the width ratio (<i>W</i>) of surface texture. After introducing random asperity structures on the micro-textured surface with a standard deviation <i>δ</i> = 0.5, the bearing capacity is increased by 44%, and the friction coefficient is reduced by 30.9%. Moreover, the introduction of half-sine rough asperity structures can only result in relatively minor differences in the lubrication performance, i.e. the changes of bearing capacity and friction coefficient are less than 10%. However, the introduction of compound hierarchical structure consisting of random asperity structures and half-sine rough asperity structures can result in an increase in the corresponding bearing capacity by 42% and a reduction in the friction coefficient by 31.1%, which implies a significant enhancement in the hydrodynamic lubrication performance.

A white-light interferometry method for 3D measurement of compactly spaced micro-nano structural units

Micro-nanostructures refer to technologies that operate at the nanoscale and provide materials and devices with unique mechanical, physical, and chemical properties. These structures have diverse applications in fields such as microelectronics, biotechnology, aerospace, and metamaterials. As precision machining technology advances, the demand for smaller sizes and higher accuracy of structural units has increased, leading to more compact integration. Consequently, the lossless and high-precision 3D measurement of highly integrated micro-nanostructure components has become increasingly challenging. In this study, we analyzed measurement errors in compactly spaced microstructural units using white-light scanning interferometry and proposed an algorithm to optimize this technology. By combining coherent peak-histogram processing with signal correlation analysis, we were able to improve the measurement accuracy by approximately ten times compared to current mainstream algorithms. To validate our algorithm, we performed experiments using metasurfaces with structural unit spacing at the order of sub-micrometer. The results obtained demonstrated the effectiveness of our algorithm in achieving accurate measurements.

Research on Precision Machining Technology of Thin-walled Parts

Precision machining of thin-walled parts has always been a problem worth exploring in machining industry. Thin-wall parts are parts with relatively thin wall thickness, which are usually used in high-precision mechanical devices, aerospace equipment, automotive parts and other fields. Thin-wall parts are difficult to process and require high manufacturing technology. There are many difficulties and challenges in processing and manufacturing. Moreover, the deformation prediction technology is very important in the processing or clamping process of thin-wall parts, which can help manufacturers predict and optimize the design and processing technology of parts, so as to improve the accuracy and quality of parts and reduce the production cost.

Influence of post-processing milling conditions on the machinability and residual stresses evolution of LPBF 18Ni300 maraging steel

Metal additive manufacturing (MAM) currently allows the production of mechanical components with technical specifications suitable for structural applications with a high level of complexity. Despite the most recent technological developments, additively manufactured parts may still lack the geometrical and dimensional accuracy as well as surface integrity required for precision mechanical assemblies and system reliability. These requirements often lead to post-processing operations through precision machining technologies. The present work focuses on the machinability study of 18Ni300 maraging steel obtained by laser powder bed fusion and its comparison with the conventional counterpart. Milling tests were carried out covering a wide range of cutting parameters, aiming at understanding their influence and comparing the obtained results in terms of cutting force, specific cutting pressure, roughness and chip morphology. In depth residual stresses have been measured for different operational and metallurgical conditions and their comparison was performed. A more significant effect of the feed parameter on the analysed data is noticed, particularly regarding the affected layer depth of the residual stresses due to cutting. Moreover, the higher mechanical strength of the additively manufactured alloy does not translate into an equivalent increase in the required average specific cutting pressure.

The Application of Mechanical Design and Manufacturing Technology and Precision Machining Technology in the New Period

The Application of Mechanical Design and Manufacturing Technology and Precision Machining Technology in the New Period

Precision Machining Technology of Jewelry on CNC Machine Tool Based on Mathematical Modeling

Abstract This article establishes the actual movement mathematical model of CNC machine tools for the precision processing of jewelry. Through analyzing the general geometric error analysis model of CNC machine tools with less than five axes and the method of solving precision CNC instructions, the operating principle of the CNC machine tools is studied. At the same time, we use a transformation matrix to express the relationship between the various moving bodies. The article abstracts the complex motion relationship between entities as the relationship between mathematical matrices. The experimental results show that the theoretical method proposed in this paper can increase the machining accuracy of the machine tool by more than 50%.

Modern Mechanical Design and Manufacturing Technology and Precision Machining Technology and Analysis

Modern Mechanical Design and Manufacturing Technology and Precision Machining Technology and Analysis

Modern Mechanical Manufacturing Technology and Precision Machining Technology

Modern Mechanical Manufacturing Technology and Precision Machining Technology

Application of Modern Mechanical Manufacturing Technology and Precision Machining Technology

Application of Modern Mechanical Manufacturing Technology and Precision Machining Technology

Analysis on Design and Manufacturing Technology and Precision Machining Technology of Woodworking Machinery

High speed machining (HSM) has become a development trend of modern manufacturing industry. It can not only significantly improve the production efficiency of products, but also greatly improve the machining accuracy and surface quality of production parts and reduce the production cost. Wood processing involves many processing processes such as sawing, milling and drilling. The compact four head motorized spindle can basically meet the milling and drilling requirements of wood processing. This paper studies the design, manufacturing technology and precision machining technology of woodworking machinery. This paper mainly adopts the finite element analysis method and applies the finite element analysis software ANSYS Workbench to simulate and model the woodworking four head high-speed motorized spindle, then analyzes and calculates its dynamic and static characteristics, and comprehensively considers the main influencing factors on the dynamic and static characteristics of motorized spindle. The test results show that the method proposed in this paper is of great significance to improve the actual working performance of motorized spindle.

Analysis on the Application of Modern Mechanical Manufacturing Technology and Precision Machining Technology

Analysis on the Application of Modern Mechanical Manufacturing Technology and Precision Machining Technology

Analysis of Mechanical Design and Manufacturing Technology and Precision Machining Technology

Analysis of Mechanical Design and Manufacturing Technology and Precision Machining Technology

Design and characterization of a copper microchannel heat sink for SiP cooling

With the increasing flourishing of miniaturized, multifunctional, and heterogeneously integrated system in package (SiP), heating problem is becoming more and more serious. In this paper, to meet the heat dissipation needs of the chips thus assembled and to achieve effective thermal management, linear, serpent and spiral shaped microchannel heat sinks were designed and fabricated into copper substrate by electrical discharge machining (EDM) and precision machining technology, acting both as the cooler and mounting base for passive and active SiP interposers. A test platform was set up to characterize the heat dissipation performance of the copper-based microchannel heat sink. The experimental and simulation results show that heat dissipation rate increases with the increasing heat flux density in the range 5–30 W/cm2 for the three microchannel designs, and the peak temperature can all be kept below 340 K (67[Formula: see text]C) even for the highest heat flux. The three designs are compared from the perspective of peak temperature, temperature distribution uniformity and pressure drop. In all, the solution proposed hereby provides a new and optimal option for in-situ cooling for densely integrated electronic hardware.

Discussion on Modern Machinery Design and Manufacturing Technology and Precision Machining Technology

Discussion on Modern Machinery Design and Manufacturing Technology and Precision Machining Technology

Parameter tuning of robust adaptive fuzzy controller for 3D elliptical vibration-assisted cutting

Abstract. Elliptical vibration cutting (EVC), as a precision machining technology, is used in many applications. In precision machining, control accuracy plays an essential role in improving the machinability of difficult-to-machine materials. To improve the control accuracy, dynamic and static characteristics of the system need to be tuned to obtain the optimal parameters. In this paper, we use a glowworm algorithm with an improved adaptive step size to tune the parameters of a robust adaptive fuzzy controller. We then obtain the optimal controller parameters through simulation. The optimal solution of the controller parameters is then applied to a 3D EVC system model for simulation and closed-loop testing experiments. The results indicate that a good agreement between the ideal curve and the tracking signal curve verifies the optimality of the controller parameters. Finally, under certain cutting conditions, the workpieces of three different materials are cut with two different cutting methods. The study revealed that the surface roughness value is reduced by 20 %–32 %, which further verifies the effectiveness of the optimal controller's parameters.

Discussion on the Application of Modern Mechanical Manufacturing Technology and Precision Machining Technology

Discussion on the Application of Modern Mechanical Manufacturing Technology and Precision Machining Technology

Optimization of Casting Process of Headstock Based on Numerical Simulation

In this paper, the casting process optimization design of a certain type of headstock is carried out by numerical simulation technology of casting process. Designed the pouring plan based on theoretical calculation; based on the numerical simulation results, quantitatively designed the riser size, and rationally arranged the pouring riser system based on the equilibrium solidification theory, which can reduce the shrinkage porosity and shrinkage defects in the casting process and increase the process yield; Finally, a sand core production plan is provided based on the precision machining technology of the moldless casting mold, which provides a new idea for the process plan design of complex spindle box castings.

Solar PV Market Research and Industry Competition Report

Solar Industrial scale continues to expand. The world installed photovoltaic capacity gradually increased from 135GW in 2013 to 480GW by the end of 2018, achieved 3.5 times growth during five years. There will be still have space for price reduction. With the development of solar cell structure design, micro-nano laser precision machining and other technologies, the per-kilowatt cost of photovoltaic power generation has entered decline channel, and it is expected to realize the affordable online in the future. According to IHS, the price difference between PERC single crystal components and polycrystal components is $0.055 per watt. Industrial technology has made obvious progress, and single crystal PERC has become the mainstream. The efficiency of the cell is breaking new records. The conversion efficiency of ordinary single-crystal and polycrystalline cells has reached 20.2% and 18.6% respectively, and the efficiency of high-efficiency batteries has reached 21.3% and 19.2% respectively. According to data released by Solarbe, the single crystal PERC technology performs best in cell conversion efficiency and output power compared with other technologies. In the next four years, China's market growth will remain stable at 40-50GW. IHS Markit forecasts that the global market size is expected to remain stable at 100-120GW from 2018, while the growth of the Chinese market will remain stable at 40-50GW in the next four years.