Lamination of local electroplating film enables three-dimensional shape generation with a smooth surface and without heat affected layers. In this paper, we attempted a method to generate a three-dimensional shape by laminating electroplating with an electrolyte suction tool. In the equipment for local electroplating, the workpiece is fixed on an X-Y-Z stage, the plating solution is circulated in the electrolyte suction tool, and the copper plating is only performed on the selected area of workpiece surface under the tool tip. The electrolyte suction tool is mainly made of one tool electrode and one acrylic resin part that surrounds the tool electrode. Experiments for the lamination shaping were performed by increasing the reciprocal scanning number with the electrolyte suction tool, and the potentiality for three-dimensional shape generation was investigated and discussed. The results showed that the three-dimensional shape generation could be performed by scanning the electrolyte suction tool without scattering electrolyte. Also, the electrode volume wear ratio of Au electrode was similar to that of carbon fiber electrode, and the wear ratio was quite small and under 2 %. The price of carbon fiber is about one five hundredth compared with that of Au. Therefore, the utility of carbon fiber is very high in this research. In addition, the height of electrodeposit was increased in proportion to the number of round trip scanning of the electrolyte suction tool. However, it was found difficult to build a stable laminating height higher than 300 μm due to magnification of the protrusion.

Aiming at the problem of camshaft torsional oscillation caused by the torque of the engine camshaft spring, this paper carries out the research on the compensation of the elliptical pulley timing system for the torsional oscillation of the camshaft. In the quasi-static state, a dual overhead gasoline engine drive system model is established, and the increments of the tight and slack side belt lengths, the arc length of the pulley wrap angle and the direction angle of the pulley tangent point are studied. The relationship of the harmonic increments is determined. Based on the structure of fixed and automatic tensioners, a mathematical model of the elliptical eccentricity and the initial phase angle for compensating the harmonic oscillational torque of camshaft spring is proposed. The simulation results verify the correctness of the model. It is concluded that the elliptical eccentricity and the belt tension amplitude of the fixed tensioner are 50% smaller than the automatic tensioner, which reduces the dynamic excitation of the system. The tension distribution of the tight side and the slack side of the belt meshed with the elliptical pulley is different. The amplitude of the tension difference between the tight and side sides belts corresponding to the automatic tensioner is twice as large as that of the fixed tensioner. At the same time, the difference in tension will cause different elongation of the belt pitch between the tight and the slack sides, causing the meshing interference between the belt teeth and the elliptical pulley groove. Therefore, the tension distribution of the belt meshed with an ellipse is completely different from that of a circular pulley.

The application of semi-solid metal forming technology to the production of high-quality copper alloy parts has attracted more and more attention. Accordingly, as the key and foundation of semi-solid metal forming technology, it is particularly important to stably and efficiently prepare copper alloy semi-solid slurry with high quality. The purpose of this study was to innovatively optimize the process parameters by combining multiple optimization algorithms to stabilize the preparation of high-quality CuSn10P1 semi-solid slurry. And the self-developed Fully Enclosed Melt-Constrained Cooling Inclined Plate (FEMCIP) device was taken as the experimental equipment. Based on the optimization method of neural network genetic algorithm, the parameters of the preparation process of CuSn10P1 semi-solid slurry were optimized by combining orthogonal experimental design, grey correlation analysis method and Latin hypercube sampling, and using the finite element analysis software ProCAST and data analysis software MATLAB with the average shape factor as the evaluation index. By comparing with the slurry before optimization, numerical simulation results and experimental verification results, it was found that the semisolid slurry prepared by the crucible with preheating temperature of 990°C, cooling water flow rate of 680.517 L/h, cooling channel angle of 45°, inclined plate length of 300 mm and quasi-isothermal time of 42.715 s had the best quality. In this research, the semi-solid slurry of CuSn10P1 alloy with uniform microstructure and high roundness of solid particles was prepared by using this optimization method, which provided a new optimization strategy for the preparation of semi-solid metal slurry by using inclined plate type equipment.

Sheet metal forming is one of the important manufacturing technologies to produce metal parts. Tearing and wrinkling are major defects in sheet metal forming, and they should strongly be prevented for the high product quality. A constant blank holder force (BHF) is conventionally used for successful forming, but the variable blank holder force (VBHF) that the BHF varies during the forming process has attracted attention and has been recognized as one of the advanced manufacturing technologies. However, it is difficult to determine the VBHF trajectory for successful sheet forming without defects. In other words, a trial-and-error method is so widely used to determine the VBHF trajectory. In addition, blank shape also affects the product quality. In this paper, the blank shape and the sloped VBHF trajectory are optimized simultaneously. To determine them, a multi-objective optimization is performed. Numerical simulation in sheet metal forming is so intensive that sequential approximate optimization is adopted to determine them, and the Pareto-frontier is then identified. An automotive part provided from NUMISHEET2011 (BM3) is selected for the application of the proposed approach. The optimal blank shape and the optimal sloped VBHF trajectory is determined through the numerical simulation. It is found from the numerical result that the optimal blank shape minimizing earing without tearing and wrinkling can be obtained.

The aim of this paper is to study the modeling method of the geometric variations which occur at the successive set-ups of the machining process by relying on the small displacement torsor (SDT) and its transfer formula, and to develop the machining process evaluation method based on the limitation of functional tolerances. The proposed method firstly considers the machining process of the mechanical part as a mechanism mainly consisted of machine-tool, part-holders, machined part, and cutting tools; Then, the SDT parameters are employed to represent the geometrical variations of the part caused by the positioning errors and machining operations during successive machining set-ups; the SDT chains are used to model the deviation propagation between different set-ups. During the whole modeling, there are three kinds of torsors need to be defined which are the global SDT of the part-holder, machined part or machining operation relative to their respective nominal positions, the gap torsor between two contact surfaces, and the deviation torsor of the associated surface relative to their respective nominal positions on the part-holder, machined part or machining operation. After obtaining all SDT chains based on the process planning of the part, an evaluation method is developed to verify the effectiveness of machining process by cumulating the impacts of various manufacturing variations on the respect of functional tolerances. Finally, an example is given to illustrate how to use the proposed method to model the manufacturing variations and evaluate the machining process of the part in the field of CNC milling machining.

To minimize the earing incurred by the planar anisotropic properties of sheets, a non-uniform die clearance model was proposed for the cup drawing process. The theoretical earing profile height model with non-uniform die clearance was developed based on the combination of radial strain and thickness strain. The Hill 1948 yield criteria was applied to predict geometric earing profile and the anisotropic parameters were calibrated by optimization. It is observed that the predictions of the theoretical model are in agreement with the results of the cup drawing experiments, and the earing profile height is increasingly decreased by the non-uniform die clearance model. Further to this, a numerical model of the deep drawing process was also carried out using the commercial finite element software Abaqus. The results show that the cup drawing with non-uniform die clearance can not only minimize the earing profile height but also reduce the opening springback and twist springback in the split-ring process.

A rolling planning method for a two-stage logistics system under unsteady demand is proposed in this paper, which has two objectives. The first objective is to propose a mathematical model that estimates the optimal production quantities, delivery quantities, and inventory level to control stock-out and over-stock situations in a make-to-stock production system to minimize the total logistics cost. The second objective is to generate optimal routes to minimize the distances travelled while delivering products from centroids to stores when the truck capacity is limited. To achieve the second objective, a mathematical model is proposed for clustering stores which integrates the geographical locations of the stores, its unsteady demands, and the truck capacity. After clustering, the travelling salesman problem (TSP) technique is applied to generate the optimal route and travelled distances within the cluster. The proposed model and solution approach are implemented in an urban area in the numerical examples. The results show that the proposed model performs well in handling unsteady demands by minimizing the total logistics cost and controlling stock-out, and over-stock situations over the planning horizon.

Flat flanges are sealed using a gasket, used to prevent leakage between the static surfaces. Gaskets comprise synthetic materials such as rubber, copper alloys, and plastic and they are inserted between two planes to strengthen the sealing performance. Leakage is circumvented by the elastic and plastic deformation of materials. However, it can be difficult to reduce leakage because of the rough nature and waviness of the solid surface; moreover, excessive clamping force may lead to surface damage. Leakage is directly proportional to the cube of the gap height and inversely proportional to lubricant viscosity. Viscosity is strongly dependent on temperature; the lower the temperature, the higher the viscosity. Thus, it is possible to control the leakage by changing the temperature of sealing parts to enhance the sealing performance of gaskets. In this paper, a flange-type gasket system with a gap is modeled using two circular plates with a central recess. Using a prototype, the effects of plate temperature, recess pressure, gap height, plate parallelism, sealing width, oil viscosity grade, and the vibration frequency and amplitude are experimentally examined under steady-state and harmonic vibration conditions. In parallel, the thermo-hydrodynamic lubrication (THL) and iso-viscous (IV) theories are applied to the gap flow and theoretical simulation was conducted. The theoretical results based on THL and IV theories agreed with the experimental data for a wide range of conditions including controlled temperature, viscosity grade, effective sealing size, inclined angle, and vibration parameters. Accordingly, this study shows that leakage can be decreased by cooling the sealing parts of gasket for all the included parameters under static and vibration conditions.

Integrated circuits industry is inherently linked to the national economy development and the security national defense in China. Its product quality and productivity as bottleneck resolutions are crucially depended on the performance of microelectronic equipment motion platform. However, motion platforms face a series of requirements including high-acceleration, ultra-precision positioning and so on. These requirements can be theoretically addressed by a typical macro-micro driving concept platform. Therefore, kinds of motion platform are proposed and Implemented. In the process of exploring analysis of macro-micro motion platform, especially for some key structures such as link frames, flexible hinge mechanisms, etc., many effective multiphysics coupling optimization methods are proposed to obtain superior performance of platform. Meanwhile, the vibration suppression of macro-micro motion platform is described to ensure ultra-precise positioning. At last, the development trends and facing problems of macro-micro motion platform are suggested. This review will promote the upgrading of microelectronics manufacturing equipment and accelerate the rapid development of microelectronics manufacturing industry.

High-power gears are widely used in various engineering fields. A gear transmission system is an extremely complex elastic system that produces complex vibrations under internal and external excitation. In this study, the excitation value in the gear was obtained based on the dynamic characteristics, stiffness, and error excitation, which were used as the input signals of the discrete element analysis. The dynamic model of the gear transmission system was established using the discrete element method. Meanwhile, the gear transmission energy was dissipated through the configuration of a particle damper in the gear. The continuous-discontinuous dynamic coupling method, which is the equivalent displacement mapping of gear contact loads from the discontinuous domain to the continuous element node, was realised, and the transformation of the local coordinates to the global coordinates was conducted. Finally, the effect of the particle restitution coefficient on the vibration reduction of gearboxes at various speeds was explored and verified through an experiment. At low rotating speeds, the best vibration reduction effect was achieved when the particle restitution coefficient was 0.2. At high rotating speeds, the best restitution coefficient was 0.7.

Since the evaporator system has been wildly applied in industry, its operating performance needs to be optimized to reduce energy consumption. Considering the evaporator, duct and fan as basic module, the matching relationship of these components must be analyzed and discussed. In this paper, to improve the design efficiency in module structure, the method to identify the design parameters and establish their mapping relationship is presented, and the structural design model of rectangular duct with finned evaporator is given. After analyzing the structural parameters of evaporator and fan in air cooling duct, the structural design of the evaporator and duct fan is identified in three geometrical parameters, which are the basic design variables in this evaporation structure. First, the simulation model of duct fan and evaporator is established, and air flow and heat distribution under variable structural parameters is simulated and compared with the experimental data gathered from the refrigeration module platform. Then, the relationship between three structural parameters and operating performance (the heat transfer and fan power) are discussed, and this quantitative mapping model is established as the design reference for evaporation structure. Finally, the optimized design is given with the energy performance evaluation in the evaporation and duct module, and this optimized design results are proposed as the structural parameter references in the case study.

This study focuses on the formation of a single-line track in selective laser melting (SLM), based on the powder morphology, size distribution, and characteristics. A chromium-molybdenum-vanadium steel, AISI H13, was used as a metal powder. The relationship between the powder morphology, size distribution, and the powder-bed layer characteristics, such as the thermal conductivity and laser absorption under a N₂ or Ar atmosphere, was determined. Subsequently, its effect on the built width, height, and contact angle was investigated by observing the cross-sectional profile of the structure. Finally, the powder morphology, size distribution, and characteristics were linked to the processability in SLM and were found to be closely related to the powder-bed layer characteristics, which affects the first deposition layer of the SLM H13 steel. The effect of the atmosphere on the contact angle is notable. The use of the Ar atmosphere to fabricate the continuous and stable structure at the minimum volume specific energy density (VSED) is reasonable because of its thermal property. The powder morphology, which depends on the atomization method, yields a variation in the bulk density and thermal property of the powder bed layer. The powder bed layer with the irregular powder can be influenced by the atmospheric characteristics because of its low bulk density. The effect of the powder-size distribution on the contact angle depends on the powder morphology. The spherical powder can perform the low-contact angle for a lower VSED.

In this paper, a novel type of adaptive loading ball traction drive reducer (AL-BTDR) is proposed and investigated in modeling and efficiency performance. A combination of power flow and equal linear velocity method is developed to evaluate the speed ratio for the first time. Meanwhile, the spin loss at contact areas is also analyzed based on the Hertz contact theory, and a new approach depended on power flow is introduced to establish the efficiency model. By applying the efficiency model, the performance of efficiency with different output torque is calculated, and the distinctions under adaptive loading and constant loading are investigated. The results show that AL-BTDR has an excellent efficiency performance under adaptive loading with a maximum of 91%. Additionally, efficiency is higher under adaptive loading and will not sharply drop when compared with constant loading.

CFRP materials are widely used in special environments, and it has excellent mechanical properties. However, CFRP processing is very difficult, especially in the process of using traditional cutting methods, due to its heterogeneity and anisotropy. In this work, based on the failure mechanism of CFRP materials, we studied the cutting mechanism of the cutters in milling processing, modeled and analyzed the milling cutters and processing materials, and conducted orthogonal milling experiments of CFRP composite materials. Based on the experimental data, the influence of different machining parameters on the cutting force was studied, and the relationship between the influence of different cutting methods on the cutting stress and cutting heat on the life of the milling tool was obtained. According to the angle between the fiber orientation and the cutting edge of the cutting edge, the cutting behavior of single fiber and CFRP unidirectional laminate is classified. The failure modes of CFRP materials under different processing behaviors are predicted and analyzed, and the theoretical model is simulated by the finite element method. The CFRP milling process and failure process are theoretically analyzed, and the milling failure process and failure forms are summarized. Through the finite element simulation of the failure process and the section observation under the scanning electron microscope, the cutting mechanism of the CFRP material is analyzed, which provides a reference for optimizing the milling parameters and optimizing the mechanism.