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A Co–Cr–Mo alloy with predominantly martensitic structure was prepared by selective laser melting (SLM), where the amount of martensite formed in the SLM specimens is much larger than in the cast samples which can be ascribed to the high density of internal defects such as dislocations and SFs. We observe a hierarchical microstructure spanning over different length scales, consisting of remelted zones and track core regions at the macro-scale, regions with elongated columnar grains and equiaxed grains at the micro-scale, martensitic laths at the submicron-scale, and a high density of dislocations and stacking faults at the nano- and atomic scale. The hierarchical microstructure leads to the outstanding tensile properties of the as-prepared SLM and SLM annealed samples (with yield strength, ultimate tensile strength and fracture strain of ~ 735 MPa, ~ 1211 MPa and ~ 12.8%, and ~ 893 MPa, ~ 1214 MPa and ~ 13.8%, respectively). The mechanisms determining the strength and ductility are discussed in terms of the hierarchical microstructure and internal defects. The cellular structure with a high density of dislocations along their boundaries and the martensitic structure are the reasons for strengthening, while the hierarchical microstructure helps to obtain appropriate ductility. Furthermore, martensitic transformation induced plastic bending of the residual FCC plates was confirmed, which is helpful to maintain the different plastic strain between the heterogeneous structure. The development of the martensitic structure in this Co–Cr–Mo alloy by SLM and its characteristic hierarchical microstructure are promising features for material design and application of high-strength materials with improved strength‒ductility tradeoff.

The changing world market requirements and perspective drives the need for new approaches and models to the development of distributed control applications. An advanced industrial automation system is becoming increasingly sophisticated with multiple levels of control and automation. A distributed control application platform was designed [Chen, IM (2001)]. The control and communication mechanism for implementation of a distributed control application platform (DCAP) is detailed. Function block (FB) based control mechanism was highlighted for the implementation of control applications. Three types of communication methods were identified to provide data exchange channels for long-term history information, short-term and real-time data between CAs. The standard communication interfaces to field devices and other industrial standard system were implemented.

With the availability of powerful embedded CPU, it is possible to integrate multiple proprietary devices and field-buses into a system. This paper proposed the CDM (common device model) as a universal model for the devices and field-buses. With the universal interface of CDM, the system could manipulate the data from/to the devices in a universal way. CDM is composed of two parts: common device interface and device drivers. The novel model has been applied for robot control based on the distributed control application platform.

During the development of advanced manufacturing systems and industrial automation equipments, the developer has to consider a lot of Control Applications (CA). There are always growing need, for manufacturers to improve their capacity and flexibility to quickly respond to market requirements by designing novel CAs, modifying legacy ones and integrating them together. In the paper, Distributed Control Application Platform (DCAP) is presented as a control platform for developing CAs of advanced manufacturing systems. The DCAP can collect data over a heterogeneous control network from any device. The DCAP can then control, monitor and optimize the operations of the systems, whether for large and complex plants or for simple and single-user devices. The DCAP provides a software framework and tools to develop and deploy CAs for complex manufacturing systems. With the help of the DCAP, it is easy and fast to build complex control systems. A modular robot based manufacturing work cell system is adopted as a case study and the DCAP is used to develop CAs for the system.

This paper addresses various issues related to design and deployment of a Web-enabled distributed control application platform for industrial automation. The built-in Web functions enable programming and execution of remote control applications through a Web browser. New control applications can be created and existing control applications can be reconfigured and tuned on the fly. A case study is also described.

A wide variety of fieldbuses have been set up in the industrial automation system in different time periods under different environment. Therefore, during the development of industrial automation systems and control applications, the developer has to consider the interconnection of heterogeneous fieldbuses. In the paper, a heterogeneous fieldbuses interconnection architecture (HFIA) is presented to interconnect heterogeneous fieldbuses. With the help of the HFIA, it is easy and fast to interconnect heterogeneous fieldbuses. At the same time, the HFIA can be used for high-level industrial applications to control, monitor and optimize the operations of the fieldbuses systems. Profilbus, CANbus and Ethernet/IP are adopted as case studies for the HFIA architecture.