Experimental investigations of influence on grain size and cold deformational behavior of AL6063 during the microforming process

Miniature products are requisite to make micro creation widely in electronics and micromechanical products. The microfabrication process is identified to satisfy the production of such miniature products rather than an ordinary manufacturing process. Microextrusion is one of the microforming processes in micromanufacturing. In this present work, an attempt has been made to investigate the influence of grain size and deformation behavior of Al6063 microstepped pin with annealed billets for the cold extrusion process. The methodology on the characterization of the microextrusion of Al6063 includes, annealing of the billet, extrusion testing, microhardness examination and surface roughness analysis. The billet with three different sizes of grains is extruded. The experimental result shows that the deformation load and average microhardness of the AA96 (annealed Al6063 with an obtained grain size of 96 μ m) are high compared to AA208 (annealed Al6063 with an obtained grain size of 208 μ m). The surface finish has improved using diamond-like carbon (DLC) coated die compared to uncoated and lubricated dies. DLC coating with AA208 billet achieved a maximum pin length of 13.1 mm, and uncoated die with AA96 billet achieved a minimum pin length of 5.5 mm. Thus, the findings of this study contribute to the fundamental understanding of cold microextrusion of aluminium 6063 alloy

Experimental investigations of influence on grain size and cold deformational behavior of AL6063 during the microforming process

Abstract Miniature products are requisite to make micro creation widely in electronics and micromechanical products. The microfabrication process is identified to satisfy the production of such miniature products rather than an ordinary manufacturing process. Microextrusion is one of the microforming processes in micromanufacturing. In this present work, an attempt has been made to investigate the influence of grain size and deformation behavior of Al6063 microstepped pin with annealed billets for the cold extrusion process. The methodology on the characterization of the microextrusion of Al6063 includes, annealing of the billet, extrusion testing, microhardness examination and surface roughness analysis. The billet with three different sizes of grains is extruded. The experimental result shows that the deformation load and average microhardness of the AA96 (annealed Al6063 with an obtained grain size of 96 μm) are high compared to AA208 (annealed Al6063 with an obtained grain size of 208 μm). The surface finish has improved using diamond-like carbon (DLC) coated die compared to uncoated and lubricated dies. DLC coating with AA208 billet achieved a maximum pin length of 13.1 mm, and uncoated die with AA96 billet achieved a minimum pin length of 5.5 mm. Thus, the findings of this study contribute to the fundamental understanding of cold microextrusion of aluminium 6063 alloy.</jats:p

Single Point Incremental Sheet Forming of Polymer on Computer Numerically Controlled (CNC) Milling Machine Tool

The idea of incrementally forming sheet metal with a single point tool, called ‘dieless forming’, was patented by Leszak [1] well before it was technically feasible. There have been many studies, which have lead to the present situation [2-9]. The new processes are attractive because manufacturing sheet metal can be accomplished by any facility having a three-axiscncmill. Sheet metalspifis an innovative, flexible sheet metal-forming technology that uses principles of layered manufacturing. It transforms the complicated geometry information into a series of parameter of two-dimensional layers and then the plastic deformation is carried out layer-by-layer through the computer numerically controlled. The basic principle ofspif(Fig. 1) is that the forming tool moves around the outline of the part along the predefined tool path and extrudes the sheet metal point by point so that the local plastic deformations occur incrementally [8, 10]. The forming tool paths have a great effect on the surface quality, forming time and dimensional accuracy. Although the movement mode of the forming tool is similar to one of the cutters in thecncmilling machine, the forming process based on the plastic deformation and milling process is totally different, so the requirements for the tool paths are different. As a result, there are some specific characteristics which should be considered in forming tool path generation. The goal of this paper is to evaluate the possibility of producing low-cost polymer sheet components by means ofspif. Three different thermoplastic materials were incrementally formed on a conventionalcncmilling machine. Experiments are conducted to determine the formability, failure modes and significant process parameters. Even though considerable amount of research work has been done in the field, these aspects are not completely defined and only limited number of materials has been tested.</jats:p

Influence of temperature on deformation behavior of copper during microextrusion process

Micro scale deformational behavior of metals is improved upon increasing the room temperature. Further, the drawbacks of micro forming caused by size effects are reduced significantly. In the current work, investigation on the material behavior of copper at elevated temperature ranging from room temperature to 200  ℃ is conducted. On the experimental part, a novel micro extrusion die set assembly has been developed along with temperature assistance, where the specimen is heated within the die assembly to study deformation behavior. When the forming temperature is raised, an enlargement of the forming limits is achieved along with a significant reduction in extrusion force. Further, the flow of material inside the die orifice was more uniform, and the micro pin showed a good replication of the die dimensions with homogeneous material deformation. During the increase of extrusion temperature and lubrication conditions (diamond-like carbon coating), the micro pin is more complete with higher dimensional accuracy and surface finish. The investigation on the influence of temperature showed that there is a reduction in microhardness of samples compared to the hardness of samples extruded at room temperature. However, there is a significant reduction of scattering due to homogenizing effect. </jats:p

Tribomechanical performance of MgO–ZnO nanoparticles as lubricating additives in the microextrusion process

The interfacial friction between tool and workpiece is unpredictable in the micromanufacturing process. It has a major influence on process workability, which determines product formability. In this study, the microtribological behavior of MgO–ZnO mixed metal oxide nanoadditive lubricant with dry friction is investigated in the microextrusion process. In the microextrusion of aluminum 6063 gear, the extrusion force reduced significantly upon using the nanoadditive lubricant. The surface roughness result shows the improved surface quality due to the existence of nanoadditives in the micromanufacturing process. The quantitative deviation due to interfacial friction is resolved with different coefficients by performing the numerical evaluation. This research contributes to the fundamental understanding about the tribological and mechanical behavior of nanoadditive lubricant in the microextrusion process and facilitates in minimizing the interfacial friction. </jats:p