W.B. Lee

A knowledge-based supplier intelligence retrieval system for outsource manufacturing

Knowledge management is to promote business success through a formal, structured initiative to improve the use of knowledge in an organization, in which an effective organizational memory information system plays an increasingly important role. Unlike the past, the performance of an enterprise now depends much on the performance and relationship of its customer–suppliers in the value chain. Good customer–supplier relationships are important for an organization to respond to dynamic and unpredictable changes. This paper describes a knowledge-based supplier selection and evaluation system, which is a case-based reasoning decision support system for outsourcing operations at Honeywell Consumer Products (Hong Kong) Limited in China. As a result, collaborative suppliers are identified quickly during the new product development process. By using the system, the cumulative performance of suppliers is constantly updated automatically according to past practice. This means that the knowledge of suppliers can be retained, categorized, retrieved and managed effectively.

A theoretical and experimental investigation of surface roughness formation in ultra-precision diamond turning

In this paper, a model-based simulation system is presented for the analysis of surface roughness generation in ultra-precision diamond turning. The system is based on a surface roughness model which takes into account the effect of tool geometry, process parameters and relative tool-work vibration. It is evaluated through a series of cutting experiments. The results indicate that the system can predict well the surface roughness profile and the roughness parameters of a diamond turned surface under various cutting conditions. With the use of the spectrum analysis techniques, the system can also help to analyze the effect of vibration on the surface quality of workpiece and to diagnose the machine faults. The potential application of the system in process optimization is also discussed in the text.

Characterisation of nanosurface generation in single-point diamond turning

This paper describes a parametric analysis of nanosurface generation in single-point diamond turning (SPDT). The properties of the surface roughness profiles were extracted and analysed using the power spectrum analysis method. A series of face cutting experiments was undertaken on an aluminium alloy under various cutting conditions. The results indicate that the power spectrum of a surface roughness profile is basically composed of several periodical components that can be correlated to different process parameters and mechanisms of surface generation. Moreover, it is found that the tool feed, tool geometry, spindle error motions and relative vibration between the tool and the workpiece are not the only dominant components contributing to the surface generation in SPDT. Materials swelling and tool interference are other important factors. Based on these findings, relationships are proposed to explain the influence of tool interference on the variation of the spectral components and process parameters. The implications of these findings on the optimisation of the surface quality in SPDT are also discussed.

A dynamic surface topography model for the prediction of nano-surface generation in ultra-precision machining

Abstract Materials induced vibration has its origin in the variation of micro-cutting forces caused by the changing crystallographic orientation of the material being cut. It is a kind of self-excited vibration which is inherent in a cutting system for crystalline materials. The captioned vibration results in a local variation of surface roughness of a diamond turned surface. In this paper, a dynamic surface topography model is proposed to predict the materials induced vibration and its effect on the surface generation in ultra-precision machining. The model takes into account the effect of machining parameters, the tool geometry, the relative tool–work motion as well as the crystallographic orientation of the materials being cut. A series of cutting experiments was performed to verify the performance of the model and good correlation has been found between the experimental and simulation results.

A web-based collaborative product design platform for dispersed network manufacturing

Abstract Many multi-national companies have operations in geographically different locations. They need to communicate and work concurrently on large amount of complex product data with their factories, sub-contractors as well as suppliers across the border. The use of e-mail and fax are far from satisfactory as they are time consuming and ineffective. In this paper, a web-based collaborative product design platform is proposed which enables authorized users in geographically different locations to have access to the company’s product data such as product drawing files stored at designated servers and carry out product design work simultaneously and collaboratively on any operating systems. There is no need for the users to install any utility software at their ends since the access is based on a remote screen sharing technique built upon a Browser/Server and thin client technology. This results in substantial saving in the cost and the product development time in a network environment.

Applications of virtual manufacturing in materials processing

Abstract Virtual manufacturing (VM) is an emerging technology that mimics real manufacturing operations with models, simulations and artificial intelligence. VM is a knowledge and information-based technique developed in recent years. With the use of the VM technologies, many aspects of the activities can be integrated and realised into one system. The manufacturing cost and time-to-market can be reduced. The associated technologies of VM and their key techniques related to materials processing and current research work are highlighted. Emphases are placed on the social and technological aspects in the development of VM systems. Some practical application examples of VM in materials processing are presented.

Study of factors affecting the surface quality in ultra-precision diamond turning

Abstract This paper deals with an investigation of the process factors and the material factors affecting the surface roughness in ultra-precision diamond turning. The process factors involve cutting conditions, tool geometry, and relative tool-work vibration which are related to the cutting geometry and the dynamic characteristics of the cutting process. The material factors considered are material anisotropy, swelling, and crystallographic orientation of the work materials. Experimental results indicate that the influence due to the process factors can be minimized through a proper selection of operational settings and better control of dynamic characteristics of the machine. The material factors, on the other hand, exert consistent influence on the surface roughness which can not be minimized solely by an optimization of process parameters and machine design. Based on these findings, some suggestions are proposed for the optimization of the surface quality in ultra-precision diamond turning.

A theoretical and experimental investigation of surface generation in diamond turning of an Al6061/SiCp metal matrix composite

Abstract In this paper, the surface generation in ultra-precision diamond turning of Al6061/15SiCp metal-matrix composites was investigated based on different analytical approaches which include parametric analysis, cutting mechanic analysis, finite element method (FEM) analysis and power spectrum analysis. Parametric analysis was performed to explore the in situ inter-relationships between the process parameters and the surface roughness. The surface properties of the diamond turned surface were extracted and analyzed by the power spectrum analysis of the surface roughness profiles. Different surface generation mechanisms were deduced based on the cutting mechanics and FEM analysis. The results of the theoretical analyses were verified through a series of cutting tests conducted under various cutting conditions and a good correlation between the theoretical and experimental results was obtained.

Design and fabrication of intelligent composites based on shape memory alloys

Abstract Shape memory alloys (SMAs) possess both sensing and actuating functions, shape memory effect, pseudo-elasticity, high damping capability and other remarkable properties. By combining SMAs with other advanced materials, intelligent or smart composites can be fabricated which can utilize the unique properties of the individual bulk materials and exhibit multiple responses. This paper overviews the principles, the basic design concepts and the fabrication of SMA composites, with an emphasis on SMA thin films and multilayer heterostructures. SMA fibers and particulate-reinforced composites. Also, some key technical problems to be solved are discussed.

A Microplasticity Analysis of Micro-Cutting Force Variation in Ultra-Precision Diamond Turning

This paper describes a microplasticity model for analyzing the variation of cutting force in ultra-precision diamond turning. The model takes into account the effect of material anisotropy due to the changing crystallographic orientation of workpieces being cut. A spectrum analysis technique is deployed to extract the features of the cutting force patterns. The model has been verified through a series of cutting experiments conducted on aluminum single crystals with different crystallographic cutting planes. The results indicate that the model can predict well the patterns of the cutting force variation. It is also found that there exists a fundamental cyclic frequency of variation of cutting force per revolution of the workpiece. Such a frequency is shown to be closely related to the crystallographic orientation of the materials being cut. The successful development of the microplasticity model provides a quantitative means for explaining periodic fluctuation of micro-cutting force in diamond turning of crystalline materials.