CN103707396B - A kind of method of precision manufactureing ultra-thin-wall honeycomb ceramic carrier extrusion molding mould - Google Patents

Abstract

The invention belongs to field of machining, particularly a kind of method of precision manufactureing ultra-thin-wall honeycomb ceramic carrier extrusion molding mould.Comprise the following steps: first adopt machining technique manufacture mould steel base substrate to be processed into the basic profile of extrusion molding mould, then adopting wire cutting technology to process mould inside stria, carrying out pre-grinding by extruding the internal rooved face of pug afterwards.Mould is immersed bath trough, and immersed by mould in bath trough, plate protective coating at mould inner surface, thickness of coating is accurately controlled by sedimentation time.Finally by mould heat treatment in argon atmosphere, formed and there is nanocrystalline and amorphous composite microstructure.Final acquisition has the extrusion molding mould of high dimensional accuracy, high rigidity, wear-resisting, anti-corrosion, self-lubricating property.

Description

A method for precision manufacturing of ultra-thin-wall honeycomb ceramic carrier extrusion molding die

technical field

The invention belongs to the field of mechanical processing, in particular to a method for precisely manufacturing an extrusion mold for an ultra-thin-walled honeycomb ceramic carrier.

Background technique

With the continuous improvement of the level of industrialization, the share of motor vehicle exhaust pollution in urban air pollution is getting higher and higher. Motor vehicle exhaust control technology has great social significance for energy saving and emission reduction. Catalyst-coated honeycomb ceramic substrate is one of the keys to the treatment of gasoline vehicle exhaust, and the particulate filter based on honeycomb ceramics is a key technology for the purification of diesel vehicle exhaust particulate matter.

In recent years, global environmental regulations and standards have been upgraded, and the requirements for honeycomb ceramic carriers have also been continuously improved, requiring higher mesh numbers and thinner wall thicknesses for honeycomb ceramic carriers. The existing 600cpsi and 400cpsi ceramic carriers can no longer meet the requirements of further technology, and the market still needs ultra-thin-wall honeycomb ceramic carriers with higher mesh number and thinner wall thickness (such as above 900cpsi). At present, the manufacturing process of the honeycomb ceramic carrier in production mainly includes steps such as mixing materials, mud refining, extrusion molding, drying, and sintering. The difficulty and key technology restricting the development of ultra-thin-walled honeycomb ceramic carrier in the prior art lies in the manufacture of high-quality, high-precision extrusion molds. At present, machining and wire cutting are generally used as the main manufacturing technology of this kind of mold, but there are many problems in this method that make it difficult to produce ultra-thin-walled honeycomb ceramic substrates, such as the difficulty in controlling the size of the small inner grooves, which makes it difficult to extrude regular shapes and walls. Thick and precise ultra-thin-walled honeycomb ceramic carrier, poor wear resistance makes the dimensional accuracy drop sharply after repeated use, and is easy to corrode, so that severe corrosion will occur if it is not used for a long time, and the mold will be scrapped. Therefore, in order to manufacture new ultra-thin-walled honeycomb ceramics, it is necessary for the mold to have the advantages of high dimensional accuracy, wear resistance of the inner wall, good corrosion resistance and self-lubricating properties.

Contents of the invention

The object of the present invention is to provide a method for manufacturing honeycomb ceramic carrier extrusion molding mold, the obtained mold has the advantages of high dimensional accuracy, good inner wall wear resistance and self-lubricating properties, and can be used to prepare new thin-walled honeycomb ceramic carrier.

A method for manufacturing a honeycomb ceramic carrier extrusion molding die, comprising the following steps:

(1) Manufacture by machining technology to process the mold steel body into the basic dimensions of the extrusion mold;

(2) The fine groove inside the mold is processed by wire cutting process;

(3) Install the preliminary mold on the extrusion equipment, extrude the ceramic mud, pre-grind the surface of the inner tank, and then remove the mold for the next step of processing;

(4) Immerse the mold in the plating solution tank, control the pH of the plating solution to 1~5, and the temperature at 60~95°C under the optimized conditions, control the circulation of the plating solution in the solution tank and apply ultrasonic oscillation during the coating deposition process, Use the deposition time to control the precise coating thickness;

(5) After the coating deposition is completed, take out the mold, clean and dry;

(6) Heat the mold at 300-600°C for 2-8 hours in an argon protective atmosphere.

In this method, the components of the plating solution are nickel sulfate 15~30g/L, copper sulfate 3~20g/L, cobalt sulfate 2~20g/L, sodium tungstate 1~10g/L, sodium hypophosphite 25~40g/L, lemon Acid 0.1~0.5mol/L, sodium silicate 10~15g/L, acetic acid 1~4g/L.

The surface of the mold prepared by the method has a layer of high hardness, wear-resistant and corrosion-resistant, self-lubricating coating, and the size of the fine groove can be precisely controlled. This method solves the problems existing in the mold manufacturing by the existing wire cutting process, and can manufacture high-quality extrusion molding molds.

Description of drawings

Fig. 1 is a flowchart of the steps of the initial machining process of the mold manufacturing process;

Fig. 2 is a schematic diagram of mold electroless plating process;

Figure 3 is the microstructure observed by the coating transmission electron microscope.

detailed description

Firstly, the die steel body is processed into the basic shape of the extrusion molding die by machining technology (as shown in Figure 1), and then the fine grooves inside the die are processed by wire cutting technology, and the width of the grooves is strictly controlled. Then install the preliminarily made mold on the extrusion equipment, extrude 20kg of ceramic mud, pre-grind the surface of the inner tank, then remove the mold, and immerse the mold in the plating solution tank (as shown in Figure 2), where the plating The main components of the liquid are: nickel sulfate 18g/L, sodium hypophosphite 35g/L, copper sulfate 5g/L, cobalt sulfate 5g/L, sodium tungstate 2g/L, citric acid 0.3mol/L, sodium silicate 13g/L L, acetic acid 2g/L. Control the pH of the plating solution to 2 and the temperature at 65°C, control the circulation of the plating solution in the solution tank through an external mechanical pump, and apply ultrasonic vibration during the deposition process of the plating layer. After 3 hours of deposition, a 20 μm thick film is obtained on the inner surface of the mold. dense coating. Take out the mold from the plating solution tank, clean and dry it, then heat-treat the mold at 350°C for 4 hours in an argon protective atmosphere, so that the coating has a corrosion-resistant and wear-resistant amorphous-nanocrystalline composite structure (as shown in Figure 3) . The Vickers hardness of the test coating can reach more than 1000, and it has good wear resistance and corrosion resistance.

Claims (3)

1. A method for precisely manufacturing an ultra-thin-walled honeycomb ceramic carrier extrusion molding die, characterized in that it comprises the following steps: (1) Manufacture by machining technology to process the mold steel body into the basic dimensions of the extrusion mold; (2) The fine groove inside the mold is processed by wire cutting process; (3) Install the preliminary mold on the extrusion equipment, extrude the ceramic mud, pre-grind the surface of the inner tank, and then remove the mold for the next step of processing; (4) Dip the mold into the plating solution tank, the composition of the plating solution in the plating solution tank is nickel sulfate 15~30g/L, copper sulfate 3~20g/L, cobalt sulfate 2~20g/L, sodium tungstate 1 ~10g/L, sodium hypophosphite 25~40g/L, citric acid 0.1~0.5mol/L, sodium silicate 10~15g/L, acetic acid 1~4g/L; (5) After the coating is deposited, take out the mold from the bath, clean and dry it; (6) The mold is subjected to heat treatment, the heat treatment process is carried out under an argon protective atmosphere, the heat treatment temperature is 300-600° C., and the holding time is 2-8 hours. 2. A method for precision manufacturing an ultra-thin-walled honeycomb ceramic carrier extrusion molding die according to claim 1, characterized in that in the coating deposition process described in step (5), the pH of the plating solution is 1 to 5, and the temperature is kept At 60~95°C. 3. A method for precision manufacturing of ultra-thin-walled honeycomb ceramic carrier extrusion mold according to claim 1, characterized in that during the coating deposition process in step (5), the plating solution circulates in the plating solution tank, and Ultrasonic oscillations need to be applied.