Multi-stage and robot assisted incremental sheet metal forming: a review of the state of art and comparison of available technologies
Incremental sheet metal forming is a recently innovated technology of achieving asymmetric sheet metal parts without using a die and through computer numerical control machine tool based path programming by inducing localized plastic deformation with a spherical ended tool. One of the major limitations of the existing method of incremental sheet metal forming is the limiting wall angle, where a wall angle of greater than about 70° is difficult to obtain. The recently proposed solution of multi-stage incremental forming can enable obtaining wall angles close to 90° but it takes longer manufacturing time and may pose problems for materials that severely strain harden. Robot-assisted incremental forming has a potential to offer an alternative solution for steel wall angle limitation but the existing work in the literature on robot-assisted incremental forming mostly focused only on the use of a standalone robotic manipulator instead of the limiting 3-axis CNC vertical machining center or a more expensive 5 or 6-axis vertical machining center. In this paper a review and comparative study of existing multi-stage incremental forming and robot-assisted incremental forming technologies in solving the limiting wall angle problem is presented.
Increasing the part accuracy in dieless robot-based incremental sheet metal forming
Abstract Roboforming is a dieless, incremental, robot-based sheet metal forming process for cost-effective manufacture of prototype parts and small batch sizes. Its principle is based on flexible shaping by means of a freely programmable path-synchronous movement of two industrial robots driving workpiece-independent forming tools. The novelty of this process leads to a huge need for further research. The main task is to increase the geometrical accuracy which is primarily influenced by the compliance of the involved serial robot structures and the springback effects of the workpiece. An offline model-based and an online sensor-based strategy to increase part accuracy are presented.
InTlP — a proposed infrared detector material
In1−xTlxP is proposed as a promising material for infrared detectors. A number of key optical and structural properties are studied within local density‐functional theory. In1−xTlxP at x=0.67 and In1−xTlxAs at x=0.15 are estimated to have a gap of 0.1 eV. Their binding energies are larger than that of InSb, and they are found to form stable zinc‐blende alloys for all x. In1−xTlxP nearly lattice matches to InP, and offers the potential to integrate detector array and read‐out circuit.