Papers by Keyword: Metal Spinning

Abstract: Metal spinning on NC machine-tools is a very flexible and complex manufacturing method which has a high efficiency for small series of parts and prototype parts. The algorithms used for calculating the roller trajectory during the metal spinning process are usually complicated and hard to apply into production. This article presents an original application developed using Visual LISP that can be used for calculating and then simulating and testing the roller trajectory in the case of manufacturing rotational complex parts by metal spinning. The simulation prevents any errors that can occur during the process of manufacturing before the parts are actually put into production.

Abstract: Sheet metal spinning is one of the forming processes based on gradual shaping of metal blank into an axisymetric part by a roller according to a mandrel. Very significant feature of spinning is ability to produce components with high mechanical properties and high quality of surface layers. The paper brings the results of major true strains analysis of mild steel parts produced by CNC multi-pass conventional metal spinning. The influence of the spindle speed, feed rate, workpiece geometry and planar anisotropy of the blank on the strain distribution of formed part is studied by method of grain size measurement. The design of experiment using the Taguchi approach and analysis of variance (ANOVA) is applied to find optimal process parameters.

Abstract: Sheet metal spinning is one of the forming processes based on gradual shaping of metal blank into an axisymetric part by a roller according to a model (mandrel). Very significant feature of spinning is ability to produce components with high mechanical properties and high quality of surface layers. The paper brings the results of surface integrity analysis of mild steel parts produced by CNC multi-pass conventional metal spinning. The influence of the spindle speed, feed rate, workpiece geometry and planar anisotropy of the blank on the residual stresses distribution and microhardness of formed part surfaces is studied. For experiment design, an orthogonal array L27(3¹³) was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the geometry of the formed part (radius, conical area, cylindrical area) is the significant factor influencing both residual stresses and microhardness of the formed part surfaces.

Abstract: Metal spinning can be used to produce hollow, axially symmetric sheet metal parts with low tooling and production costs, high flexibility, and low waste. Spinning parameters determine the quality of the spinned parts and are of interest for enabling the spinning of thick sheet metals. In this study, conventional metal spinning was conducted on a 6 mm thick low carbon steel with process below its recrystallization temperature to fabricate tube head, requiring maximum deflection of about 90º at its edge. Spinning parameters varied were temperature (at room temperature and 300°C), feed (2 mm and 5 mm), and spinning speed (200 rpm and 250 rpm). Evaluation was made on the resulted surface morphology, thickness variation, and further analysis on hardness and microstructure of the spinned tube head. The resulted tube heads were of acceptable quality in terms of surface morphology and thickness variation, while hardness and microstructure analysis showed that inner parts of the workpiece were not affected by the spinning process.

Abstract: The paper brings the results of roughness analysis of formed part produced by CNC multi-pass conventional metal spinning. The influence of the spindle speed, workpiece geometry and planar anisotropy of the blank on the formed part roughness was studied. For experiment design, an orthogonal array L27(313) was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the higher spindle speed leads to rough surface finish. The surface roughness measured in different areas of experimental samples (corner R10, conical area, cylindrical area) indicates that the worst surface finish is in the conical area. Roughness in different directions refer to the sheet rolling direction shows minimal differences.

Abstract: The paper brings the results of wall thickness distribution analysis of formed part produced by CNC multi-pass conventional metal spinning. The thickness reduction was measured by optical 3D scanning method and the influence of the feed, workpiece geometry and planar anisotropy of the blank on the wall thickness reduction was studied. For experiment design, an orthogonal array L27 was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the highest reduction of wall thickness is observed in the conical part of the experimental sample. Workpiece geometry is the most important factor which influences the wall thickness variation.

Abstract: The paper presents the results of radial strain distribution measurement throughout the part after multi-pass conventional metal spinning by the circle grid analysis method. The influence of the mandrel speed, workpiece geometry and planar anisotropy of material on the radial strain was studied. For experiment design, an orthogonal array L27 was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the sequence of factors affecting radial strain corresponds to geometry of spun part, mandrel speed, planar anisotropy of the sheet. In particular, it is found that the workpiece geometry (specific areas of spun part: mandrel/workpiece radius, conical area, cylindrical area) is the most important factor which influences the radial strain of the spun part.

Abstract: Today, the components of smart structures consisting of structural and smart materials are generally produced separately and assembled in additional processes afterwards. An alternative approach, which combines the forming of metallic parts and the assembly of the structures in one process step, is proposed in this paper. Incremental forming processes are applied for this operation. Significant joining mechanisms will be analyzed and some applications of this combined forming and assembly process are shown. As sensors, smart components allow a monitoring of appearing loads, as actuators they allow an active influencing on appearing disturbances. The research contains numerical analyses and experimental tests.

Abstract: Spin-forming is a new near net-shape forming process for cup-shaped thin-walled inner gear (CTIG). The CTIG spinning was investigated by numerical simulation and processing experiments. The results show that the compressive deformation along tangential direction on the internal surface of part leads to a reduction in root circle of spun part; and the local loading and friction work result in the nonuniform radial deformation on the external surface of spun part. For spin-forming of CTIG with a small number of teeth, the diameter reduction is feasible for improving the forming quality of tooth groove, while the nonuniform radial deformation would cause concaves on external surface of part. For spin-forming of CTIG with a large number of teeth, the diameter reduction is not conducive to removing the part from the mandrel.