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Technology for Obtaining Samples of Layered Composite Materials with Metallic Matrix
Dumitru Nedelcu,Ioan Carcea 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.1
Layered composite materials significantly improved the mechanical process of fracturing, which means better fracture strength, while preserving surface properties such as hardness, resistance to wear and resistance to high temperatures. The properties are significantly influenced by the interphase mass transfer at the surface matrix-fiber reinforcement. We developed a mathematical model to determine the molar flux at the interface in stationary and in a nonstationary regime. The technological parameters are: hydraulic pressure,reinforced material, alloy type, fiber diameter, mass ratio between the reinforcement and the composite masses and mould preheating temperature. A mould patented in Romania was mounted on a hydraulic press to obtain the samples. We studied the material structure, matrix and fiber element distribution, metallic matrix element distribution and matrix and fiber element content variation. The results recorded revealed a 75% to 120% increase of the fracture strength, which means an improvement of the mechanical process of fracturing. We concluded that the reinforcement material, mass ratio and fiber diameter have a significant influences on the fracture strength.
Development of Real-time Grinding Process Monitoring and Analysis System
Saurabh Kumar,Hong-Seok Park,Dumitru Nedelcu 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.8
The success of the manufacturing process which involves grinding as one of the stages depends solely on the accuracy of the grinding process. Being the last stage of the manufacturing path, it is mostly done to provide the desired surface finish to the product. This makes the stage very crucial. To prevent the ruining of all the previous stages and eff orts, the real-time monitoring of the grinding stage becomes necessary which will make a room for better production planning and avoidance of failure occurrence. Conventionally the quality is dependent on the machine behavior as well as the operator’s skill. To make the process in par with the latest industry 4.0, real-time process monitoring of the grinding process with the use of a vibration sensor is considered. The developed system in the paper focusses on the monitoring of the process behavior and log the occurred changes. The hardware architecture and software modules are introduced in detail and the application of the developed system is demonstrated with the grinding of an automotive part. The developed system is convenient to use and very helpful in improving the overall productivity of the brake disc production facility by reducing the quality failures and hence saving the resources.