Theory And Method Of Green Product Assessment And Its Application In Powder Metallurgy

Green manufacturing is a characteristic of manufacturing industry in 21 century. Green product is an essential element in green manufacturing. Powder metallurgy is a kind of precision-formation technology which is used widely, and its products are used in more areas. Materials and products in manufacturing industry are taken as the object of research in this paper. Its aim is to establish indicator system of green product in powder metallurgy and its evaluation. Based on the research results of eco-material and green product at present, the uniform system structure of green product evaluation was established for mechanical products. Theories and methods on environmental evaluation, energy evaluation, resource evaluation, cost evaluation and quality evaluation, which belong to green attribute evaluation, were developed. Theories and methods on comprehensive greenness evaluation and implementing process evaluation were also developed. Then these theories and methods were applied to powder metallurgy. Methods on powder metallic green product evaluation in green manufacturing were developed. A example of connecting poles of engine was studied. Design framework of powder metallic product integrated formation system was developed. Results and conclusions are as follows:(1) Through analyzing the relevant research fruits now, in the scope of green product about material and product in manufacturing industry, the concept of green product referring to benefit in economy, society and environment was defined. Its characteristics of environment, energy, resource, cost and quality were distinguished. Its evaluations were divided into comprehensive greenness evaluation, green attribute evaluation, life cycle based evaluation and implementing process evaluation. Characteristic model of green product evaluation, which has attribute, space and time dimension, was set up. Then system structure of green product evaluation was established. Subject content and meaning of green product evaluation were analyzed. System framework of indicators in green product evaluation was developed.(2) Through studying the up-to-date research fruits of LCA, product environmental problems were classified according to methods on midpoint and endpoint evaluation in LCA. On the basis of system framework of indicators in green product evaluation, methods on midpoint evaluation for environmental evaluation and resource evaluation(including energy evaluation), which belong to green attribute evaluation , were developed. Considering the valuation about LCIA profile which is bottleneck in the application of ISO14042, the nonlinear artificial neural network model of valuation about LCIA profile was developed, which avoids the influence of uncertainty on determination of weighting factors.(3) Through analyzing the present methods on product cost analysis, according to product life cycle and perspective of assessment and on the basis of system framework of indicators in green product evaluation, general framework and assessment principle of product costs were established, and methods on quality evaluation were developed considering the green attribute evaluation about environmental, energy, resource and cost.(4) Condition on which evaluation methods are applied to comprehensive greenness evaluation was given. After analyzing the drawbacks on common comprehensive evaluation being applied to the comprehensive greenness evaluation, comprehensive evaluation based on group gray relational analysis was developed. Using the utility of green products, comprehensive evaluation based on utility function approach was developed and its models based on BP and RBF artificial neutral network were established. As a result, it avoided the influence of uncertainty on determination of weighting factors.(5) Through analyzing green product implementing process, implementing risk evaluation in green manufacturing was put foreword. Its methods and models based on fuzzy multiple attribute decision making and group hierarchical fuzzy comprehensive evaluation were developed.(6) On the basis of above theories and methods, methods on powder metallic green product evaluation in green manufacturing were developed and the parameters in its models were determined. After investigating present manufacturing process about connecting poles of engine, 6 connecting poles of engine made by 6 different processes were evaluated. Under the center of those methods, design framework of powder metallic product integrated formation system was developed.