Nano surface engineering and remanufacture engineering

Nano surface engineering and remanufacture engineering are introduced, and the relationship between them is set forth. It points out the superiority of nano surface engineering to the traditional one, and reveals the advantages of remanufacture engineering. Taking some nano surface techniques as samples, such as nano-materials brush electroplating, nano-materials thermal spraying and nano-materials self-repairing antifriction additive technology, it shows the applications of nano surface engineering technology to remanufacturing mechanical parts.

3D reconstruction of worn parts for flexible remanufacture based on robotic arc welding

3D reconstruction of worn parts is the foundation for remanufacturing system based on robotic arc welding, because it can provide 3D geometric information for robot task plan. In this investigation, a novel 3D reconstruction system based on linear structured light vision sensing is developed. This system hardware consists of a MTC368-CB CCD camera, a MLH-645 laser projector and a DH-CG300 image grabbing card. This system software is developed to control the image data capture. In order to reconstruct the 3D geometric information from the captured image, a two steps rapid calibration algorithm is proposed. The 3D reconstruction experiment shows a satisfactory result.

Life cycle of remanufactured engines

The life cycle index of remanufactured engines was assessed by using the method of life cycle assessment （LCA）. A remanufactured engine of a certain domestic brand was taken as researching object. Engine reproducing engineering was investigated from three aspects which were energy, material and environment. The application of LCA on remanufacturing engines was discussed in detail with a practical case. The results indicate that remanufacturing an engine can save 55kg steels, 8.3kg aluminum and 113kW·h electric powers and reduce emissions of 565kg CO2, 6.09kg CO, 1.01kg NOx, 3.985kg SOx and 288.725kg solid waste. The remanufacturing of engines possesses great economic value and practicability.

Research on a Product Information Management System Facing Remanufacture Engineering

Remanufacture Engineering is an important characteristic and development trend of a manufacturing system in the 21st Century, and product information management is very important to Remanufacture Engineering. In this paper, we first compared traditional manufacturing and remanufacturing. Then, according to the features of Remanufacture Engineering, we analyzed the request of product information management system facing Remanufacture Engineering, and designed the system module. Finally, we built a kind of system structure of product information management facing Remanufacture Engineering and gave realization methods based on Web.

Manufacturers’strategy for introducing remanufactured products under a government subsidy:Introduce or not?

With strong government advocacy and encouragement,many manufacturers hope to enter the remanufacturing market.Manufacturers who have entered the remanufacturing market hope to increase their profits through effective decision-making.Using game-theoretic models,this study investigates manufacturers’conditions for introducing remanufactured products and the production decisions after the introduction by constructing a consumer utility model.Our study demonstrates that manufacturers’decision-making method directly affects their decision to introduce remanufactured products.If a manufacturer plans to introduce remanufactured products,they should adopt a centralized decision-making method for the two products.Under this decision-making method,when the ratio of the government subsidy to the cost of new products is not too large or too small,the manufacturer can introduce remanufactured products.Additionally,the range of the ratio of the government subsidy to the cost of new products is related to the difference between the ratio of the cost of remanufactured products to that of new products and the substitutability of the remanufactured products.Therefore,when formulating a subsidy,the government should control it within a reasonable range and formulate differentiated subsidy strategies based on different enterprises’specific conditions to give full play to the benefits of the government subsidy.Moreover,after the manufacturer has introduced remanufactured products,the consumer surplus and manufacturer’s profit increase with the government subsidy.However,social welfare increases only when the government subsidy is within a reasonable range.Furthermore,compared with subsidizing consumers,it is found that subsidizing the manufacturer does not affect their profit,the consumer surplus,and social welfare;however,the range within which the manufacturer can introduce remanufactured products narrows.

Assessment of fatigue life of remanufactured impeller based on FEA

Predicting the fatigue life of remanufactured centrifugal compressor impellers is a critical problem. In this paper, the S-N curve data were obtained by combining experimentation and theory deduction. The load spectrum was compiled by the rain-flow counting method based on the comprehensive consideration of the centrifugal force, residual stress, and aerodynamic loads in the repair region. A fatigue life simulation model was built, and fatigue life was analyzed based on the fatigue cumulative damage rule. Although incapable of providing a high-precision predic- tion, the simulation results were useful for the analysis of fatigue life impact factors and fatigue fracture areas. Results showed that the load amplitude greatly affected fatigue life, the impeller was protected from running at over-speed, and the predicted fatigue life was satisfied within the next service cycle safely at the rated speed.

Circular and Adaptive Transformation of the Housing Stock towards a Regenerative Future

The transition from a linear economy to a CE(circular economy)has the potential to reduce resource use,environmental impacts,and waste in the built environment.Creating a CE in the built environment is therefore of fundamental importance to achieve a sustainable society.Through the application of a systemic approach that considers the building as a set of technological subsystems(e.g.vertical closures,roof,furniture,etc.),components(e.g.infill panels),and materials,this paper-starting from a review of the literature on the topic of the CE applied to construction-establishes a framework of circular design strategies and definitions that link the VRPs(value retention processes)framework,based on the R-imperatives,to the Design-for-X strategies.The first research objective is to develop a design tool for circular building components and technological subsystems.

Plasma transferred arc forming technology for remanufacture

The plasma transferred arc （PTA） forming remanufacturing technology was introduced in this paper. This technology includes plasma surfacing, deposition and rapid forming technology. With self-developed plasma forming system, the thrust of engine cylinder body was remanufactured by PTA powder surfacing. In the concrete, the Nil5 alloy was deposited on the thrust face of the body in order to recover its dimension. In addition, the reman- ufacturing forming with Fe-based, Inconel 625 alloy was studied. The microstructure and hardness of the as-depos- ited materials were investigated.

Experimental Study on the Reduction Effect of Pit Texture on Disassembly Damage for Interference Fit

After remanufacturing disassembly,several kinds of friction damages can be found on the mating surface of interference fit.These damages should be repaired and the cost is closely related to the severity of damages.Inspired by the excellent performance of surface texture in wear reduction,5 shapes of pit array textures are added to the specimens’surface to study their reduction effect of disassembly damage for interference fit.The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows:equivalent circle diameter of single texture,texture shape and texture surface density.The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density.The circular texture with a surface density of 30%and a diameter of 100μm shows an excellent disassembly damage reduction effect because of its perfect ability of abrasive particle collection.And the probability of disassembly damage formation and evolution is also relatively small on this kind of textured surface.Besides,the load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments.The results show that the load-carrying capacity of the excellent texture surface is increased about 40%compared with that of without texture.This research provides a potential approach to reduce disassembly damage for interference fit.

Industrial Recycling Process of Batteries for EVs

The growing number of decarbonization standards in the transportation sector has resulted in an increase in demand for electric cars.Renewable energy sources have the ability to bring the fossil fuel age to an end.Electrochemical storage devices,particularly lithium-ion batteries,are critical for this transition’s success.This is owing to a combination of favorable characteristics such as high energy density and minimal self-discharge.Given the environmental degradation caused by hazardous wastes and the scarcity of some resources,recycling used lithium-ion batteries has significant economic and practical importance.Many efforts have been undertaken in recent years to recover cathode materials(such as high-value metals like cobalt,nickel,and lithium).Regrettably,the regeneration of lower-value-added anode materials(mostly graphite)has received little attention.However,given the widespread use of carbon-based materials and the higher concentration of lithium in the anode than in the environment,anode recycling has gotten a lot of attention.As a result,this article provides the most recent research progress in the recovery of graphite anode materials from spent lithium ion batteries,analyzing the strengths and weaknesses of various recovery routes such as direct physical recovery,heat treatment recovery,hydrometallurgy recovery,heat treatment-hydrometallurgy recovery,extraction,and electrochemical methods from the perspectives of energy,environment,and economy;additionally,the reuse of recycled anode mats is discussed.Finally,the problems and future possibilities of anode recycling are discussed.To enable the green recycling of wasted lithium ion batteries,a low energy-consuming and ecologically friendly solution should be investigated.

Mechanism of Cracking Resistance of Hardfacing Specimens of Steel 5CrNiMo Improved by Rare Earth Oxide

The cracking morphology of the hardfacing specimens taken from steel 5CrNiMo was observed. Meanwhile, the residual stress fields were measured and simulated. Based on experiment mentioned above, the improved structure and modified inclusion in hardfacing metal with rare earth （RE） oxide were analyzed. The results show that, the hardfacing crack is initiated from the coarse dendritic crystal grain boundary, inclusions and coarse austenite grain boundary in the HAZ and propagated by the residual stress existing in the center of the hardfacing metal and HAZ. The primary columnar grain structure can be refined by adding RE oxide in the coating of the electrode. The inclusion in the hardfacing metal can be modified as well. Meanwhile, if the martensite transformation temperature is decreased, the largest value of the residual tensile stress in the dangerous region can be reduced.

Sustainable manufacturing for obsolete computers based on 3R engineering

The volume tendency of in-use and end-of-life computers in China were analyzed; the emerging danger of obsolete computers by incorrect treatment was summarized; the integration disposal technologies based on 3R (recycle, remanufacture and reuse) engineering aiming at monitors, electronic devices, metals, plastics materials, and overall computers were put forward; the economic and social benefits were also analyzed. The results show that the integration disposal process of obsolete computer is an optimum approach to save the resource of electromechanical products. Remanufacturing and disposal 100 thousand obsolete computers per year can create profits about RMB10million yuan and provide employment for 300 persons. It can be deduced that there are great potential opportunities for the obsolete computers disposal industry containing recycle, remanufacture and reuse engineering.

Remaining Useful Life Model and Assessment of Mechanical Products: A Brief Review and a Note on the State Space Model Method

The remaining useful life(RUL) prediction of mechanical products has been widely studied for online system performance reliability, device remanufacturing, and product safety(safety awareness and safety improvement). These studies incorporated many di erent models, algorithms, and techniques for modeling and assessment. In this paper, methods of RUL assessment are summarized and expounded upon using two major methods: physics model based and data driven based methods. The advantages and disadvantages of each of these methods are deliberated and compared as well. Due to the intricacy of failure mechanism in system, and di culty in physics degradation observation, RUL assessment based on observations of performance variables turns into a science in evaluating the degradation. A modeling method from control systems, the state space model(SSM), as a first order hidden Markov, is presented. In the context of non-linear and non-Gaussian systems, the SSM methodology is capable of performing remaining life assessment by using Bayesian estimation(sequential Monte Carlo). Being e ective for non-linear and non-Gaussian dynamics, the methodology can perform the assessment recursively online for applications in CBM(condition based maintenance), PHM(prognostics and health management), remanufacturing, and system performance reliability. Finally, the discussion raises concerns regarding online sensing data for SSM modeling and assessment of RUL.

Improved Ant Colony-Genetic Algorithm for Information Transmission Path Optimization in Remanufacturing Service System

The information transmission path optimization(ITPO) can often a ect the e ciency and accuracy of remanufactur?ing service. However, there is a greater degree of uncertainty and complexity in information transmission of remanu?facturing service system, which leads to a critical need for designing planning models to deal with this added uncer?tainty and complexity. In this paper, a three?dimensional(3D) model of remanufacturing service information network for information transmission is developed, which combines the physic coordinate and the transmitted properties of all the devices in the remanufacturing service system. In order to solve the basic ITPO in the 3D model, an improved 3D ant colony algorithm(Improved AC) was put forward. Moreover, to further improve the operation e ciency of the algorithm, an improved ant colony?genetic algorithm(AC?GA) that combines the improved AC and genetic algorithm was developed. In addition, by taking the transmission of remanufacturing service demand information of certain roller as example, the e ectiveness of AC?GA algorithm was analyzed and compared with that of improved AC, and the results demonstrated that AC?GA algorithm was superior to AC algorithm in aspects of information transmission delay, information transmission cost, and rate of information loss.

Developing remanufacturing engineering,constructing cycle economy and building saving-oriented society

In the course of creating immense wealth, manufacturing industry has excessively consumed the resources and energy in the earth, and seriously polluted the environment. To take progress as the sustainable development way, save resource and improve environment, our nation has been advocating to construct the cycle economy and saving-oriented society. Taking the remanufacturing engineering as the representative, the “4R” rule (Reduce, Reuse, Recycle and Remanufacture) is the important measure to get the goal. Remanufacturing engineering is the industrialization of high-tech maintenance of the waste and worn productions, and is one of the most active factors in “4R”. The development of high and new technology takes the important effect to promote the remanufacturing engineering.

Remanufacturing Scheme Design for Used Parts Based on Incomplete Information Reconstruction

The different conditions of use of a component result in a variety of damage levels.Therefore,excluding differences in shape and size,used parts show a high degree of uncertainty regarding failure characteristics,quality conditions,and remaining life,which seriously affects the efficiency of a remanufacturing scheme design.Aiming to address this problem,a remanufacturing scheme design method based on the reconstruction of incomplete information of used parts is proposed.First,the remaining life of the reconstructed model is predicted by finite element analysis,and the demand for the next life cycle is determined.Second,the scanned 3D damage point cloud data are registered with the original point cloud data using the integral iterative method to construct a missing point cloud model to achieve the restoration of geometric information.Then,according to reverse engineering and laser cladding remanufacturing,the tool remanufacturing process path can be generated by the tool contact point path section line method.Finally,the proposed method is adopted for turbine blades to evaluate the effectiveness and feasibility of the proposed scheme.This study proposes a remanufacturing scheme design method based on the incomplete reconstruction of used part information to solve the uncertain and highly personalized problems in remanufacturing.

Remanufacturing system based on totally automatic MIG surfacing via robot

Remanufacturing system is a term of green system project which conforms to the national sustainable development strategy. With the demand of the high adaptability of the varieties of waste machining parts, the short product cycle, the low machining cost and the high product quality are offered. Each step of the remanufacturing system from the beginning of the scanning to the accomplishment of the welding was investigted. Aiming at building a remanufacturing system based on totally automatic MIG surfacing via robot, advanced information technology, remanufacturing technology and management, through the control of the pretreatment and the optimization to minimize the time of remanufacturing and realize the remanufacturing on the terminal products of varieties, were applied. The steps mainly include: 1) using the visual sensor which is installed at the end of the Robot to rapidly get the outline data of the machining part and the pretreatment of the data; 2) rebuilding the curved surface based on the outline data and the integrated CAD material object model; 3) building the remanufacturing model based on the CAD material object model and projecting the remanufacturing process; and 4) accomplishing the remanufacture of the machining part by the technology of MIG surfacing.

Path planning for MIG surfacing of robot-based remanufacturing system

Robot-based remanufacturing system can scan the worn parts and develop the corresponding models, compare them with the standard model, calculate the weld deposit, implement welding path planning, and repair the worn parts with MIG surfacing automatically. This paper investigates the welding path planning after calibrating, scanning and model rebuilding. The following aspects are contained： introducing the planning principle, selecting the suitable welding process based on welding parameters （current and speed）, calculating welding overlap quantity by the superposition method. Also, it has been verified that good weld profile can be obtained with the optimized parameters.

MODELING AND ROBUST DESIGN OF REMANUFACTURING LOGISTICS NETWORKS BASED ON DESIGN OF EXPERIMENT

The uncertainty of time, quantity and quality of recycling products leads tothe bad stability and flexibility of remanufacturing logistics networks, and general design onlycovered the minimizing logistics cost, thus, robust design is presented here to solve theuncertainty. The mathematical model of remanufacturing logistics networks is built based onstochastic distribution of uncontrollable factors, and robust objectives are presented. Theintegration of mathematical simulation and design of experiment method is performed to do sensitiveanalysis. The influence of each factor and level on the system is investigated, and the main factorsand optimum combination are studied. The numbers of factors, level of each factor and designprocess of experiment are investigated as well. Finally, the process of robust design based ondesign of experiment is demonstrated by a detailed example.

Failure analysis used for remanufacturing of steel rolling components

The guide-pieces, used in the process line of steel rolling, were the important components. The guide-pieces, which were slide contacting with the rolled-piece, had a high temperature and high speed. The wear was very serious. The results from failure analysis showed that there were three failure forms in the guide-pieces: the first was the wear during heat friction, the second was the heat fatigue under the cycle of deep heating and deep cooling, and the third was the impact rupture. Among them, the wear was the main reason. To the wear of guide-pieces, there were four mechanisms, namely abrasive wear, adhesive wear, fatigue wear and corrosion wear. The failure analysis to the guide-piece laid the foundation for its remanufacturing.