High precision molds for the replication of structured optical elements like Fresnel lenses or prism arrays are generated by diamond machining or precision grinding. In some cases surface quality of the replicated components is not sufficient to meet the increasing demands concerning surface roughness and form accuracy for optical applications. Subsequent polishing of the structures may therefore be necessary. Within this work structured molds were finished by a newly developed abrasive polishing process, by laser polishing, and by abrasive flow machining. This paper focuses on the material removal mechanisms and achievable surface quality in abrasive polishing. Surface quality is compared to that achieved by laser polishing and abrasive flow machining.
What is The Manufacturing Process of Precision Mold?
Every step in the process from the signing of a precision mold manufacturing order to the delivery of a qualified mold to the customer may affect the quality of the mold. The precision mould manufacturing process is controlled according to system engineering, and every link must be controlled. 1. Materials and heat treatment control mold parts heat treatment to achieve the required material hardness of the part, but also to make the part processing process and post-processing size and shape stable, according to the different parts of the material and parts structural characteristics, different heat treatment methods The internal stress of the heat treatment of the part must be controlled. The heat treatment process must be formulated to fully consider the hardenability of the material.
Every step in the process from the signing of a precision mould manufacturing order to the delivery of a qualified mold to the customer may affect the quality of the mold. The precision mould manufacturing process is controlled according to system engineering, and every link must be controlled.
Material and Heat Treatment Control
The mould parts heat treatment of the enables the parts to obtain the required material hardness, and at the same time, the part processing process and the size and shape of the parts can be stabilized. There are different heat treatment methods for different parts and structural characteristics of the parts. The control and formulation of the heat treatment process must fully consider the material's hardenability, hardenability, overheat sensitivity, and decarburization sensitivity. For thin-walled parts, a pressure hardening process should be used.
Precision Grinding Processing Control
Grinding is a key process for precision mould processing. For precision grinding, it is necessary to strictly control the occurrence of grinding deformation and grinding cracks, and even control the micro-cracks on the surface of the workpiece.
EDM Control
Wire cutting processing preparation: Wire cutting adopts precision slow wire cutting machine, processing accuracy ± 0.001mm, roughness Ra = 0.2um, select the deionized water cutting wire with high deionization degree. The verticality meets the processing accuracy requirements. The material of the cutting wire is adapted to the material of the workpiece to be cut, ensuring a reasonable processing speed.
Surface Treatment and Mold Assembly
Surface treatment: After finishing, the surface of the workpiece has no pores, uniform hardness, small difference in isotropic characteristics, low inclusions, and knife marks, abrasive marks, and other stress concentrations when the surface of the part is not processed. Use polishing, grinding, and bench grinding to dull the useless sharp edges of the workpiece. The surface is grayish white 6 ~ 10 m after electromachining. The hardened layer is removed, and the layer is brittle with residual stress. Before use, the hardening must be fully eliminated Floor.
Mold assembly: The workpiece should be fully demagnetized before assembly, and the surface should be cleaned with ethyl acetate. During the grinding and electroforming process, the workpiece will have a certain magnetization, with weak magnetic force, and it is easy to absorb some small debris. In the process: fully understand the structure and technical requirements of the assembly drawing, and assemble all kinds of parts; correctly list the assembly order of each part; check the dimensional accuracy of each part, and clarify the various requirements; Assembly tools; firstly install the guide post and guide sleeve of the mold frame part, and insert the mosaic molding block assembly;