Computer Simulation in Manufacturing Industry
Advanced computer simulations had been adopted quite early by aerospace and automotive sector for their process and product development. Manufacturing industry, however, had been relatively slow to adopt simulations as part and parcel of their research and development processes. With the lowered cost of computation power every passing day and availability of commercial computer programmes, simulations are becoming very popular in manufacturing industry in recent times. Simulations are coming to the rescue whenever there is a need for detailed analysis to diagnose product performance issues and if there are requirements to understand the effect of modifications to improve existing designs. Besides, advanced simulations are used more and more to evaluate various options before prototyping. As a result of these, simulations are slowly replacing traditional trial and error based methods by knowledge-driven product and process development leading to huge savings in time and cost. It is important to remember, however, that simulations are still not a substitute for physical testing. Clever use of simulation can complement physical testing by drastically reducing the number of trials during testing. Moreover, simulations can many times give a very good insight about which parameters to measure and where to measure in an experiment.
It is never an easy task to make the simulation popular in production as a problem solving tool. A wide variety of the problems reside in production in manufacturing industry and solving some of those can lead to a quick return on investment in simulation techniques. A big hurdle in the production process is to identify the problems that can be solved effectively through simulations. So, it becomes necessary at times to educate the production people about these relatively new problem solving tools. Moreover successful comparison of simulation results with measured data goes a long way in generating confidence about these techniques in produciton. There are wide variety of simulation techniques that are established today and these techniques are maturing with time and new techniques are slowly evolving. Due to the complex nature of problems in industry, many times a single simulation technique may not be sufficient to address a problem. And this calls for a multi-disciplinary approach where different simulation techniques need to talk to each other.
The process of manufacturing shaped components from metal powder is generally known as powder metallurgy. Properties of powder metallurgy products are highly dependent on the characteristics of starting metal powder. Production of components through powder metallurgy has potential advantages of near-net shape products where very little material is lost due to less need of further machining process to arrive at the final dimensions. Among several methods of metal powder production, gas atomization is one of the most popular methods. The atomized powder generally has excellent properties which are difficult to achieve by other processing routes. The benefits of rapidly solidified metal powders result from higher cooling rates achieved in the process. Production of metallic powder through gas atomization is a complex process of interaction between liquid metal and high speed inert gas like nitrogen or argon. The high speed inert gas jet breaks down the liquid metal column into fine droplets which then subsequently solidify in-flight to form metal powders.
Similarly, in most of heat treatment applications, the main requirement is to attain a certain uniform temperature within the material at a certain time. The absence of the right temperature range and uniformity can lead to unacceptable quality of final product, resulting in rejections and yield losses. Also, the process may be able to attain right temperature and uniformity but without optimum use of energy. This can result in high energy costs and lower productivity, which means lower operational efficiency. To be able to attain the right temperatures at optimum costs, a precise control of the heat treatment process is necessary. This requires a good understanding of the physical phenomena of the fluid dynamics and heat transfer within the furnaces. In the production environment, usually the temperature measurements at only a few points are used to control the process, as it is not feasible to measure at multiple locations. Moreover, it is extremely difficult to estimate the interior temperatures of the charge material. Therefore, it is necessary to have a reliable simulation model which can predict the temperature at all locations inside the furnace. On the other hand, such simulations are a must for the furnace manufacturers to know how the temperature would behave within those furnaces and whether it would meet the end customer’s heat treatment requirement. It is becoming more common nowadays for a customer to demand for a simulation model of the heating system along with the actual delivery of the system.
It is beyond doubt that the manufacturing industry is embracing computer simulations more and more as a problem solving tool. We are not far when most production processes will have a simulation model which not only will help to improve the processes but also to diagnose and troubleshoot the problems.