Surface treatment and assembly during parts production

Surface treatment and assembly during parts production

Knife marks and grinding marks left on the surface of the part during processing are places where stress is concentrated and the source of crack expansion. Therefore, after the processing is completed, the surface of the part needs to be strengthened and polished by benchwork to deal with the hidden dangers of processing. Blunt and R-shape some edges, sharp corners and openings of the workpiece.

Generally, the electrically machined surface will produce a modified hardened layer of about 6-10 μm, which is off-white in color. The hardened layer is brittle and contains residual stress. The hardened layer must be fully eliminated before use. The method is surface polishing and grinding to remove the hardened layer.

During the grinding and electrical machining processes, the workpiece will be magnetized to a certain extent and has weak magnetic force, which is very easy to absorb some small objects. Therefore, before assembly, the workpiece must be demagnetized and the surface cleaned with ethyl acetate.

During the assembly process of the mold, first refer to the assembly drawing to find all the parts, then list the order of assembly of the parts, list the matters that should be paid attention to, and then start assembling the mold. During assembly, the guide posts and guide bushes are generally installed first, then the mold frame and the male and female molds are installed, and then the gaps in various places, especially the gaps between the male and female molds, are assembled and adjusted. After the assembly is completed, the mold inspection must be carried out and an overall status report written. For the problems found, reverse thinking can be used, that is, from the back process to the forward process, from fine machining to rough machining, and check one by one until the crux is found and the problem is solved.