Análise do efeito do tratamento superficial no desgaste de um aço H13 em molde de injeção de polímeros

Abstract

AISI H13 steel is the most suitable and used for manufacturing inserts and mobile components of polymer injection molds. Due to the work requirements for this steel, the mold components are subjected to heat treatment and nitriding. The present work aimed to find a solution for the wear caused by a certain insert in a polymer injection mold, manufactured in AISI H13 steel. This hairpiece suffers drag when injecting the polymer polybutylene terephthalate (PBT) with 30% glass fiber. Three samples of AISI H13 steel were made. The first sample did not receive any heat treatment, the second sample received heat treatment and nitriding, the third sample received heat treatment, nitriding and a surface coating of DLC (Diamond Type Carbon) using the PVD (Physical Vapor Deposition) technique. of steam). A mold insert was also manufactured and received the same treatment and coating as the third sample. Hardness and metallography tests were carried out to evaluate the steel layers in the three samples. The result of the hardness test did not have a major difference between sample two and three, due to the laboratory only having the durometer available, where the ideal for this evaluation and analysis is the nanohardness meter. In the metallographic analysis, it was possible to identify the difference in the coating between the samples, making it possible to visualize the DLC in sample three and measuring the thickness of the layer where it was between 0.9 and 1.6 microns. The result of the treatment carried out on the post and put to work in the field was excellent compared to the post with only heat treatment and nitriding, which resisted 26,000 cycles and became damaged. The insert with a DLC surface coating resisted 150,000 cycles and until the completion of this TCC work it showed no signs of visual and dimensional wear. [resumo fornecido pelo autor]