Technical cost modelling for a novel semi-solid metal (SSM) casting processes for automotive component manufacturing

Abstract

The cost structure and benefits of a new billet preparation process in semi-solid metal (SSM) casting of automotive components were investigated. The process was developed by the CSIR, a government research and development agency in South Africa. It has been well established that over 70% of the total development cost of a product and its manufacturing process is decided during the design phase, although this phase accounts for less than 7% of the total costs. It is thus important to be able to predict the cost structure of a newly developed manufacturing process if it is to be considered by manufacturing enterprises for development to substitute a process that is in use. The costs of the new SSM technologies was established by technical cost modelling and was compared with the cost of two competing technologies, forging and die casting. The cost model was developed in a spreadsheet using engineering models, data from literature and information provided by process experts. Estimated engineering costs were classified accordingly as accounting costs. The developed costing model was used to estimate and analyse the total manufacturing cost for each manufacturing process, and to study how total cost is affected by other variables such production volume, cost type, etc. It was found that depending on the type of component and on production volume the CSIR SSM process can compete on cost with die casting and hot forging. It was also found that improvement in the cost competitiveness of the CSIR SSM manufacturing process can be achieved by reducing material usage during manufacturing by reducing the diameter of the runner and sprue system