Advanced Materials Research Vols. 1061-1062

Abstract: With the presentation of a fire accident caused by wire joint, this paper reveals the theory that large contact resistance at wire joint can induce high temperature, and eventually can cause fire. Through macro-examination and metallographic analysis about the melted marks of wire joint, it clarifies the formation mechanism of the melted marks, and the corresponding preventive measures which can prevent wire fires, provide a practical and reliable scientific basis to guarantee the safe operation of house power system.

Abstract: This paper mainly introduces the new CrWMoV high-alloy wear resistant cast iron prepared by the composition design, the composition proportion and the melting and pouring, and analyses its microstructure and wear resistance. Microstructures and phases of the new CrWMoV high-alloy wear resistant cast iron were analyzed by scanning electron microscopy, energy dispersive spectrometer and X-ray diffract meter. Furthermore, the Rockwell hardness, impact toughness and wear resistance of the material were also studied. The result show that the composition of the new CrWMoV high-alloy wear resistant cast iron is mainly (V, W) C particles which is synthesized in-situ and evenly distributed in the composite, as well as a small amount of (Cr, Fe) ₇C₃ phase and Fe-Cr phase. The average Rockwell hardness of the composite is about 64.5 HRC, the average impact toughness is 9.85 J/cm², and the relative wear ability of the composite is about 2 times higher than the Cr15Mo2Cu which shows good wear resistance.

Abstract: Wear behavior of AZ51 magnesium alloy was studied using a pin-on-disc type wear apparatus at 20-360 N and 0.785 m/s. Wear mechanisms were determined using scanning electron microscope (SEM), including abrasion, oxidation, delamination, thermal softening and surface melting. Microstructural evolution, plastic deformation and microhardness in the subsurfaces were examined with optical microscope and hardness tester before and after mild to severe wear transition. The subsurface microstructure experienced deformation, dynamic recrystallization (DRX) and surface melting successively with increasing load. These changes in subsurface microstructure result in strain hardening and thermally-activated softening in the near-surface layers. The thermal softening originating from DRX and surface melting in subsurface is responsible for the mild to severe wear transition.

Abstract: To realize the process information sharing and three-dimensional annotation, a standardization description model for machining process information was proposed, which including three layers, natural language description layer, object oriented language description layer and symbolic language description layer. By extension the graphical symbol of surface texture, integrated with machining allowance, surface lay and direction, surface roughness, machining method and technical parameters, equipment, fixture, cutting tools, test information, and sequence number, a graphical symbol for three-dimensional machining process information was proposed. Then formulated the annotation specification of the graphical symbol, including annotation plane, position and orientation, associativity, indication of two or more machining step, restricted area and color using. Finally, a three-dimensional machining process planning system was developed, and a part machining process annotation was taken to illustrate the validity of the graphical symbol.

Abstract: Existing pepper fruit peeling machine for peeling incomplete, improper peeling force, pit protective film damaged, lead to a high impurity rate, pit crushing, unsatisfactory color and other issues. In order to solve these problems, manufacturing pepper fruit preprocessing machine based on analysis of pepper machining process. The machine achieves pepper fruit surface damaged by differential principle, work in with pepper peeling machine to peel completely.

Abstract: A removable catalyst muffler is designed and applied according to the characteristics of general 125ml motorcycle muffler. It has advantages of convenient disassembling, simpler catalyst replacement and low cost of installation and maintenance.

Abstract: To solve the problem of difficult process data management caused by the unstable process in complex products assembly, by introducing the workflow technology, a method of multi-dimensional assembly process data management based on workflow was proposed. The evolution model of assembly process information was established from the perspectives of granularity, cycle and version. On this basis, the assembly process information organization model based on workflow was put forward. The detailed description of the management method of process data’s evolution in the perspectives of granularity and cycle was presented. The feasibility of proposed method was proved by actual engineering applications.

Abstract: With 3D Prototype model as its core, collaborative development platform is a closed loop information system focus on the process lifecycle management of requirements analysis、 product design、process design、frock design 、manufacturing execution as well as logistics integrated supporting, issues of system architecture、 information integration and fine-grained access control strategy of collaborative development platform are key research contents in this paper. firstly, a distributed system architecture of collaborative development platform is introduced to achieve flexibility、integration and interoperability. Then information integration solution between collaborative development platform and other information systems based on web service is defined and investigated, an implementation process between enterprise collaborative development platform and enterprise resource planning (ERP) via ontology and web services is presented to demonstrate the feasibility and validity of the proposed information integration solution. Finally, fuzzy trustworthiness-involved role based access control strategy (FT-RBACS) is proposed for collaborative development platform, its formalization expression and numerical algorithm are developed to implement fine-grained authorization management and access control for collaborative development platform.

Abstract: This paper considers a scheduling problem of two parallel machines with a resumable availability constraint. The objective is to minimize the makespan. The problem is NP-hard in the ordinary sense. Therefore, we need to find an approximate solution that fulfills the required error bound. To get a better approximation solution in a polynomial running time, we propose a fully polynomial-time approximation scheme (FPTAS) by trimming states space.

Abstract: Evaluating the assemblability at the design stage is important because of the cost competitiveness of company. However by compared results of the sequence of bottle neck process of production stage, the Lucas DFA (Design for assembly) and Boothroyd & Dewhurst DFA is not enough to evaluate the assenblability accurately. Therefore, in this paper, we proposed three design factors which is affecting assembly but not mentioned at DFA. These design factors would help the designers to evaluate assemblability and improve the productivity.