Mesoscale forming limit bending sample, preparation method and mechanical measurement method

Abstract

The invention provides a mesoscale forming limit bending sample, a preparation method and a mechanical measurement method, and solves the problem that the existing strain distribution measurement method of the mesoscale forming limit bending sample cannot meet the bending mechanical measurement of the sample in a low-transparency medium environment. The mesoscale forming limit bending sample is composed of a wide part clamping part and a long and narrow testing part, the wide part clamping part is connected to one end of the long and narrow testing part, and the mesoscale forming limit bending sample is characterized in that metal coating films are respectively arranged on the upper surface and the lower surface of the long and narrow testing part through magnetron sputtering; the metal coating is a plurality of micro circles with mesoscale and is distributed in an array mode, and the thickness of the metal coating does not exceed 200nm. The invention further discloses a preparation method and a mechanical measurement method of the mesoscale forming limit bending sample, and the mesoscale forming limit bending sample can be widely applied to the technical field of strain measurement.

Description

technical field [0001] The application relates to the technical field of strain measurement, in particular to a mesoscale forming limit bending specimen, a preparation method and a mechanical measurement method. Background technique [0002] With the development of microelectronics and micromechanical industries, the demand for thin-plate micro-components is increasing. However, due to the existence of the scale effect of plastic deformation at the mesoscopic scale, the plastic deformation capacity of metal thin plates is different from that of macroscopic conditions. To improve The plastic microforming process requires a systematic study of the plastic deformation behavior of metal sheets at the mesoscopic scale. [0003] Among them, since the bending process accounts for a large proportion in the thin plate plastic micro-forming process, especially in the forming process of the micro-lead frame, the micro-bending process plays an important role. In the macrobending proces...

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Problems solved by technology

However, this method is only applicable to the continuous optical path between the surface of the tested sample and the measuring lens, so this method is also unable to complete the strain measurement of the surface where the sample contacts the punch, and due to the small thickness of the thin plate at the mesoscopic scale, The bending deformation resistance is low, and the surface of the sample is relatively thickly sprayed with paint, which has a great influence on the bending mechanical properties and resilience properties of the sample, and it is impossible to accurately measure the bending deformation behavior of the metal sheet at the mesoscopic scale, so that the bending process can be further optimized restricted

[0008] It can be seen that the above two methods cannot accurately measure the strain data of the upper and lower surfaces of the sample during the bending deformation process due to their respective limitations, resulting in a reduction in the accuracy of the inability to effectively guide the optimization of the forming process

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