Meiling Wang, Qin Li, Zhiqiang Huang, Weiji Qian, Xiong Chen, Qiang Li and Tianhua Lai
This study aims to solve the premature failure of the rubber stator due to wear, reduce the frictional resistance moment of the screw pump to solve the problem of a model of…
Abstract
Purpose
This study aims to solve the premature failure of the rubber stator due to wear, reduce the frictional resistance moment of the screw pump to solve the problem of a model of Daqing oilfield screw pump oil recovery system shutdown after the difficult start.
Design/methodology/approach
For the first time, the rotor surface of a screw pump was treated with dot-matrix texture to study the effect of dot matrix texture on the tribological performance of the stator-rotor friction subsets of screw pump. Reciprocating friction tests with different texture morphologies (S-shape, double tongue) and angular parameters (0°, 45° and 90°) were conducted at 10% of the texture area and pump silicone grease.
Findings
When point texture was added to the surface of the rotor sample, the friction coefficient and wear quantity of the sample were lower than those of the surface without texture treatment, and the double tongue 0° combination showed the best tribological properties. At this time, the average coefficient of friction and wear is reduced by 22.8% and 62%, 28.6% and 64.8%.
Originality/value
The introduction of texture can effectively improve the tribological performance of progressive screw pumps, and this paper provides important theoretical and experimental support for the design of progressive screw pumps in practical applications.
Details
Keywords
A real-time production scheduling method for semiconductor back-end manufacturing process becomes increasingly important in industry 4.0. Semiconductor back-end manufacturing…
Abstract
Purpose
A real-time production scheduling method for semiconductor back-end manufacturing process becomes increasingly important in industry 4.0. Semiconductor back-end manufacturing process is always accompanied by order splitting and merging; besides, in each stage of the process, there are always multiple machine groups that have different production capabilities and capacities. This paper studies a multi-agent based scheduling architecture for the radio frequency identification (RFID)-enabled semiconductor back-end shopfloor, which integrates not only manufacturing resources but also human factors.
Design/methodology/approach
The architecture includes a task management (TM) agent, a staff instruction (SI) agent, a task scheduling (TS) agent, an information management center (IMC), machine group (MG) agent and a production monitoring (PM) agent. Then, based on the architecture, the authors developed a scheduling method consisting of capability & capacity planning and machine configuration modules in the TS agent.
Findings
The authors used greedy policy to assign each order to the appropriate machine groups based on the real-time utilization ration of each MG in the capability & capacity (C&C) planning module, and used a partial swarm optimization (PSO) algorithm to schedule each splitting job to the identified machine based on the C&C planning results. At last, we conducted a case study to demonstrate the proposed multi-agent based real-time production scheduling models and methods.
Originality/value
This paper proposes a multi-agent based real-time scheduling framework for semiconductor back-end industry. A C&C planning and a machine configuration algorithm are developed, respectively. The paper provides a feasible solution for semiconductor back-end manufacturing process to realize real-time scheduling.
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Xianping Wei and Wen Jie Zheng
This paper aims to expand the application area of Inconel 718 alloy in marine environment, the sensitivity of pitting corrosion should be analyzed and discussed, especially the…
Abstract
Purpose
This paper aims to expand the application area of Inconel 718 alloy in marine environment, the sensitivity of pitting corrosion should be analyzed and discussed, especially the effect of block carbides.
Design/methodology/approach
Effect of carbides on the sensitivity of pitting corrosion for Inconel 718 alloy was carried out at 30°C in 3.5% NaCl solution using dynamic electrochemical impedance spectroscopy and anodic polarization techniques. In addition, the initiation of pitting corrosion was investigated by immersion test in 0.05 M HCl + 6% FeCl3 solution.
Findings
As a result, the precipitation of carbides, as the initiation of pitting corrosion, increased pitting corrosion susceptibility, especially the block carbides could lead to deep-spalling. Within that process, temperature and potential acted as the main controlling factors, and the effect of the latter was more distinct.
Originality/value
The initiation of pitting corrosion was revealed by the immersion test. The mechanism of pitting corrosion was analyzed and discussed.