Qiuhong Jiang

Bio: Qiuhong Jiang is an academic researcher from Dalian University of Technology. The author has contributed to research in topics: Life-cycle assessment & Remanufacturing. The author has an hindex of 14, co-authored 28 publications receiving 508 citations. Previous affiliations of Qiuhong Jiang include Texas Tech University.

Life Cycle Assessment–based Comparative Evaluation of Originally Manufactured and Remanufactured Diesel Engines

Abstract: Life cycle assessment (LCA) enables us to estimate potential resource and energy consumption as well as environmental emissions resulting from various activities within our economy. The present LCA intends to analyze the energy consumption and environmental emissions of the entire life cycle of an originally manufactured diesel engine compared with its remanufactured counterpart. Further, the article attempts to identify the processes in diesel engine manufacturing and remanufacturing life cycles that contribute most to energy consumption and environmental impacts. Six environmental impacts were assessed in this study: global warming potential (GWP); acidification potential (AP); eutrophication potential (EP); ozone depletion potential (ODP); photochemical ozone creation potential (POCP); and abiotic depletion potential (ADP). The results show that diesel engine remanufacturing could reduce 66% of energy consumption, compared to original manufacturing. The greatest benefit related to environmental impact is with regard to ODP, which is reduced by 97%, followed by EP, GWP, POCP, AP, and ADP, which can be reduced by 79%, 67%, 32%, 32%, and 25%, respectively. In the life cycle of diesel engine manufacturing, production of materials brings about larger environmental impacts, especially with regard to EP and ODP, whereas transportation of materials contributes most to POCP. The situation is similar for diesel engine remanufacturing. Production of materials brings about larger environmental impacts with regard to AP, EP, and ODP, whereas components remanufacturing and production of materials exhibit the same amount of GWP impact. Further, in remanufacturing, the reverse logistics of old diesel engines brings about lesser environmental impacts than the other life cycle stages, except with regard to POCP.

State of the Art in Directed Energy Deposition: From Additive Manufacturing to Materials Design

Abstract: Additive manufacturing (AM) is a new paradigm for the design and production of high-performance components for aerospace, medical, energy, and automotive applications. This review will exclusively cover directed energy deposition (DED)-AM, with a focus on the deposition of powder-feed based metal and alloy systems. This paper provides a comprehensive review on the classification of DED systems, process variables, process physics, modelling efforts, common defects, mechanical properties of DED parts, and quality control methods. To provide a practical framework to print different materials using DED, a process map using the linear heat input and powder feed rate as variables is constructed. Based on the process map, three different areas that are not optimized for DED are identified. These areas correspond to the formation of a lack of fusion, keyholing, and mixed mode porosity in the printed parts. In the final part of the paper, emerging applications of DED from repairing damaged parts to bulk combinatorial alloys design are discussed. This paper concludes with recommendations for future research in order to transform the technology from “form” to “function,” which can provide significant potential benefits to different industries.