| 35steel have appropriate strength,good the craft function and weld function so much characteristic, as a result,which is extensively used on rubber mold. Rubber tire mold are work in heat, pressure,chemistry causticity and the friction environment.such as wood grain and groove etc.It is very easily to stores rubber and remain vulcanization thing in the mold, they will not only influence the surface shape of tire, but also decay a molding tool’s service life, because the surface glues to attach and undergoeswear away during its service timet, then have to be dismantle and unloaded to clean, whcih will decrease the service life of tire molding tool and increase production cost, therefore there are important realistic meaning to raise the anti-adhesion properties of the mold surface.The tire mold equipment is a big physical volume and complicated structure, the surface request high quality characteristics to come to a decision its whole equipments should not be manufactured by high performance material, the modern surface technique passes to give the molding tool surface the special composition, structure and function and effectively raise the strength, hardness and anti-adhesion properties of mold surface.Tire mold surface treatment on the purpose of maintaining the original performance of the mold surface and then give it the new performance, the tire mold production process, the subject of the proposed blasting method on35steel tire moldplated by evaporation and then subjected to surface treatment on an aluminum dense layer by discussed the type of shot peening process, by varying the peening pressure, spray pressure time, the diameter of the projectile, the role of distance, the cleaning step, the degree of vacuum plating, the drying time, materialsthe hardness of process such as the organizational parameters impact of micro-nano structure formed on the surface of the tire mold, micro-nano structure aluminized layer the behaviors of abrasion resistance, anti-adhesion properties, resistance to sulfide pollution.The thesis of main research is as follows:1.By experimental analysis to determine the material surface micro-nano hybrid structure, the optimization of the vacuum coating process parameters, including the pressure of the spray pill, spray pressure time, projectile diameter, the role of distance, the cleaning process, the coating vacuum, drying time, hardness of raw materials. To test the hardness properties of the coating of micro-nano composite layer, the data indicate that the use of shot peening technology, under the combined action of the grain refinement and work hardening the substrate surface hardness and the hardness of the heart compared to obtain a significant increase, enhance the hardness from the original220Hv to about310Hv, wear resistance, mold release performance has improved significantly.2. Pass roughness testing experimental analysis of micro and nano structure vacuum coating composite layer roughness investigated. The data show that with a large diameter steel shot peening treatment, improve work efficiency, reduction of working hours, but the sample surface roughness; polishing and then the small-diameter steel shot, roughness decrease with time. Therefore, in order to reduce the surface roughness of the workpiece to meet the engineering requirements, availability projectile diameter gradually decreases the the multiple booster shot peening method. A certain degree of surface roughness of the surface of the curing material can suck some air bubbles to promote the reduced contact area and reduce the possibility of contamination of the chemical reaction generated by the contact.3.Study on friction properties of micro and nano structure of vacuum coating composite layer. Experimental results show that35original steel coefficient of friction approximately is0.80, the values in the coefficient of friction of about0.45after shot peening, shot peening and aluminized approximately0.6. Material is configured by a smooth surface micrometers to nanometers both by mixing the surface of the concavo-convex structure coexist, not only increases the contact area of the surface of the material and other media, and change lubrication environmental conditions, but also show that the hardness is increased, the two, by joint action of reducing the coefficient of friction and improve the wear resistance of the mold material, prolong the life of the mold.4.Make use of a vulcanized experiment in flat panel to imitate a rubber mold for producing tire undergo service circumstance, compared to the original sample and shot peening specimen, shot peening curing of the plating sample contamination. An aluminum film formed on the surface layer of the sample into the shot peening coating treatment, the aluminum is in an air self-passivating metal and its oxide cover layer capable of forming a layer of a dense oxide film. Shot peening treatment after the coating so that the aluminum atom capable with the substrate tightly binding after forming a thin film since the passivation covering the matrix material, this makes the composite layer has a good stability performance, isolated from the ion state of the substrate surface of the metal and the rubber of the chloride ion or sulfur ions or moisture from the air, an oxygen atom, such as a chemical reaction, reducing the surface energy of materials, to stabilize the chemical properties of materials. 5. The shot peening coating surface treatment technology, active in the radial tire mold block first shot peening micro and nano processing and then evaporated under vacuum aluminized to improve the surface resistance to sulfide pollution performance, according to the actual production of tire manufacturers to reflect the situation in a timely manneradjustment improved technology and the progressive realization of industrialization, with good market prospects. This has a very important significance to improve the quality and grade of the tire mold products, to increase the market competitiveness of the mold products. |
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