FEM analysis of manufacturing of a hollow product with an outer flange in a four-stage cold forming process

The paper presents the results of a FEM computer simulation of the cold forming process of a hollow sleeve forgings with an outer flange. Numerical simulations were carried out in DEFORM 2D / 3D. For the numerical calculations of the forming process the axisymmetric calculation module was used. As the test object, a tubular workpiece with an outer diameter of Ø50 mm and a wall thickness of 10 mm made of 42CrMo4 steel was used. The process of forming the rotary sleeve was conducted in four stages consisting of two technologies. The first stage of the research was the analysis and selection of parameters of the extrusion process, which was used for the first stage of forming. The processes of free extrusion and the use of a container were analysed. Furthermore different die angles and different wall thickness reductions were used. The products obtained in the extrusion process were upset in three conical blanks. The aim of the study was to analyse the numerical accuracy of the designed process of forming the hollow shaft with flange. The analysis of the results was based on the deformation intensity distribution maps, the Cockroft-Latham criterion distribution and the progress of the forming forces. On the basis of the conducted research, it was concluded that the presented process of forging a hollow product with a flange in four stages is possible to carry out correctly.

FORMATION OF HOLLOW SHAPE PORCELAIN BY USING A NEW INTEGRATED SLIP ROTARY MOULDING TECHNIQUE

Hollow ceramic product is fabricated generally using slip casting technique. The conventional processes produce slip and mould waste which require for disposal schedule. A rotary moulding technique is a feasible process for producing hollow shape ceramic product and eliminates the waste. This paper focuses formulation of the slip and process parameters of the rotary moulding for hollow ceramic product fabrication. The formulated ceramic slip is poured inside the mould rotated at 2-axis system inside a controlled chamber with specific temperature, speed and time for producing green body hollow ceramic product. This process uses minimum amount of ceramic slip and long lasting mould material which will reduce ceramic waste to environment and simplify the manufacturing process for mass production. Using small amount of polymer based dispersant and coagulant agents, experimental analysis resulted the green hollow porcelain product which was successfully removed during de-moulding process without any breaks. The hollow product produces homogeneous forms of ceramic structure after firing procedure and 1.9 MPa green strength with addition of small amount of binder.