Optimization of remanufacturing process routes oriented toward eco-efficiency

Remanufacturing route optimization is crucial in remanufacturing production because it exerts a considerable impact on the eco-efficiency(i.e.,the best link between economic and environmental benefits)of remanufacturing.Therefore,an optimization model for remanufacturing process routes oriented toward eco-efficiency is proposed.In this model,fault tree analysis is used to extract the characteristic factors of used products.The ICAM definition method is utilized to design alternative remanufacturing process routes for the used products.Afterward,an eco-efficiency objective function model is established,and simulated annealing(SA)particle swarm optimization(PSO)is applied to select the manufacturing process route with the best eco-efficiency.The proposed model is then applied to the remanufacturing of a used helical cylindrical gear,and optimization of the remanufacturing process route is realized by MATLAB programming.The proposed model’s feasibility is verified by comparing the model’s performance with that of standard SA and PSO.

Effect of processing routes on microstructure and mechanical properties of 2014 Al alloy processed by equal channel angular pressing

Al-Cu alloy was deformed through equal channel angular pressing(ECAP) by routes A,Ba,Bc and C up to 5 passes.ECAP was done using a 90° die for three different conditions,namely 1) as received,2) solutionised at 768 K for 1 h and 3) solutionised at 768 K for 1 h + aged at 468 K for 5 h.The microstructure,microhardness and tensile strength were studied for all the three conditions and four routes.Significant improvement in hardness(HV 184 after five passes) and strength(602 MPa after three passes) was observed in solutionised and aged 2014 Al alloy deformed through route Bc.Microstructure evolution was reasonably equiaxed in route Bc with aspect ratio of 1.6.Solutionised and aged 2014 Al alloy deformed through route Bc was identified to have better microstructure and mechanical property than the other processing routes and conditions.

Effect of Processing Route on the Stability of Aqueous ZrO_2 Suspensions

The relationship between processing route and suspension stability in ZrO2-H2O-PANH4 system was investigated through rheology study. The work showed that two suspensions with identical PAN H4 concentration and final solution condition but prepared by different routes differed greatly in stability. This behavior is attributed to their different distribution state of PANH4 on ZrO2 surface that is determined by the adsorption affinity depending on pH condition in solution. High affinity at pH 5.0 induces a nonuniform distribution of soluble PAA- （polyacrylicacid） on particle surface, which can flocculate the suspension strongly, while low affinity at pH 9.0 induces an uniform distribution of polymer so that the higher stabilization can be achieved. A simple mathematical model was used to account for the observed results.

Problems Encountered and Countermeasure Adopted During Processing of Shengli High-sulfur and High-acidity Crude

The centralized processing of high-sulfur and high-acidity crude has contributed to improvement of the overall economic benefits of the oil refining enterprise, but has also resulted in crude emulsification, severe corrosion of process units and environmental protection issues. The long-cycle, safe and smooth operation of process units were guaranteed after selection of optimal processing routes and adoption of a series of technical measures.

Processing,microstructure,and properties of porous ceramic composites with directional channels

Porous ceramic composites with directional microchannels from micrometer to dozens of micrometer levels have attracted more and more attention in various fields including aerospace,biomedicines,and thermal insulation due to their excellent fluid permeability,mechanical properties,etc.In this article,we summarize the recent directional porous ceramics developments including their main processing routes and respective properties.Meanwhile,the properties get from different processing routes have been com-pared and analyzed in terms of microstructures,mechanical properties,and permeability.Emphasis has been given to the deeper understanding which can allow one to control the microstructural features of these porous ceramic composites to obtain the desired characteristics.This work can provide a useful reference for the development and application of porous ceramic composites with directional microchan-nels.

Interactive Optimization of Impressive Parameters Middling in Biological Leaching

In this study, single and interactive effect of three parameters, pH, ferrous and pulp concentration has been investigated by a 2^3 full factorial CCRD （central composite rotatable design） composed of eight factorial points, six central and six axial points. Initially, ＂none＂ mode from transformation subsection was chosen as the default choice for both responses, i.e. %recovery and gram of recovered zinc. Box-Cox plots give the best Lambda for each response （y^Lambda= f （A, B, C .....）） which occur at 1.91 and 2.16 for %recovey and gram of recovered zinc, respectively. A linear （y^1.91 = f （linear）） and a quadratic （y^2. 16= f （quadratic）） equation were suggested by software as the model for %recovery and gram of recovered zinc, respectively. Analysis of variance （ANOVA） for both models shows a high coefficient of determination （R^2）. In order to optimize and find the best conditions under which three parameters occur appropriately, optimization was done numerically. Desirability plots indicate properly that the best conditions occur at pH = 1.46, ferrous = 6.67 g/L, %pulp = 7.1 （%w/v）, %recovery = 86.5, gram of recovered zinc = 0.63 g and desirability = 0.777. Finally, PRP （progressive route of the process） analysis donates us a proper insight of what is happening during these 30 days. PRP analysis categorizes flasks in two parts, 1- flasks worth economically, 2- flasks with one-time-usable feed materials.

Improved Methods for Process Routing in Enterprise Production Processes in Terms of Sustainable Development Ⅱ

The selection of process planning methods during production influences the enterprise＇s production process planning performance with determination of the process flow as the most important influencing factor. A new production process determining method that focuses on sustainable manufacturing was developed based on case-based reasoning, expert systems, and feature technology for designing the process flow of a new component. This study matches a new component with preview case process information, modifies the case process information if necessary, and selects the process flow for the new component based on a sustainable development assessment according to the similarities between the case and the sustainable development characteristics. The feasibility and practicability of the method is verified by a case study of a machining process flow design for a new component.

Recent progress in microstructural evolution,mechanical and corrosion properties of medium-Mn steel

Medium-manganese(Mn)steel(MMS)has remarkable characteristics of high strength,strong work-hardening capacity,and wear resistance,being a promising third-generation advanced high-strength steel with lower raw material cost compared with other generations of advanced high-strength steel.The chemical composition and processing route play critical roles in determining the microstructural evolution of the MMS,and the microstructure composition significantly influences the mechanical,corrosion and wear properties of the steel.Hence,a lot of research work focus on exploring the direct relation between microstructural evolution and mechanical/corrosion/wear properties,and the progress has the following crucial aspects:(1)alloying design on the phase composition and carbide precipitation,(2)processing route on regulating microstructure evolution and twinning-induced plasticity and/or transformation-induced plasticity strengthening mechanism,(3)work-hardening,corrosion,and corrosion resistance of the regulated MMS,and(4)fracture and failure mechanism of MMS under tensile,corrosion and wear damages,as well as the improvement strategies.