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How to Make Carbide Molds

Views:12     Author:Site Editor     Publish Time: 2020-11-05      Origin:Site

How to Make Carbide Molds

As the name implies, cemented carbide mould is made of cemented carbide, which can be used to make things consistent with its shape, quite useful, so how is cemented carbide mold made?


  • The production of cemented carbide mould

  • How to use cemented carbide mold


The production of cemented carbide mould

1. Mold blank processing

Cemented precision carbide mould will shrink during the sintering process. Different batch numbers have different shrinkage due to the difference in composition, pressing and sintering processes. The shrinkage of each part of the die blank often forms a "saddle" due to the difference in shrinkage. Or "bell mouth" shape. Although the fluctuations in the dimensions of the die blanks meet the standards of the die blanks, they far exceed the interference requirements during die set mounting, resulting in serious unevenness in the prestress of the die core during mounting and greatly reducing the mold life. For external cylindrical grinding, a special fixture is required on the grinder and a diamond wheel is used for grinding.


2. Installed interference

In order to obtain a certain prestress of the mold core during installation, the inner hole diameter of the mold sleeve should be smaller than the outer diameter of the mold core, and the difference between the two is called the interference. The amount of interference should be determined according to the die core size and deviation, drawing stress and inserting method. The die set is inlaid with two kinds of hot pressing method and cold pressing method. The cold pressing method has a small interference and a small pre-pressing stress. It is mostly used to make small-sized wire drawing dies for drawing soft metals.


3. Precision carbide mould set processing

The die sleeve is formed by turning on a lathe, and the control points during processing are as follows:

(1) The inner diameter roughness of the die sleeve must reach 0.80-I. 6 m, which is conducive to close cooperation with the mold sleeve;

(2) The inner diameter of the mold sleeve must correspond to the outer diameter of the mold blank to ensure the accuracy of the interference of each mold;

(3) The bottom surface of the inner hole of the mold sleeve and the outer end of the mold must be parallel, and ensure that it is perpendicular to the center line of the mold hole after the sleeve is installed;

(4) The ovality of the inner hole of the die sleeve should be as small as possible, and should not be greater than 0.02 mm. The outer surface of the mold sleeve should be polished during hot assembly to ensure uniform cooling after assembly.


4. Installation process

The assembling process of the cold pressing method is to press the mold blank into the mold sleeve with a press at room temperature. The cold pressing method requires accurate interference and high dimensional accuracy of the mold core and mold sleeve. The advantage is that it does not require heating equipment, saves energy and reduces consumption costs.

Because the production process of cemented carbide dies is not fixed, the cemented carbide dies can be customized according to customers' requirements. The application scope of custom carbide mould is relatively simple, but the matching degree with fixed machine will be higher, and you can also produce what you want, so you should decide whether to customize custom carbide mould according to your own needs.


How to use cemented carbide mold

1. Inspection and maintenance of cemented carbide mold before machine:

(1)    According to the size of the punching shear force of the carbide mould, correctly use a punch with sufficient tonnage. (Generally, the tonnage of the machine tool must be greater than the punching shear force of the die)

(2)    Before the cemented carbide mold is put on the machine, the gap of the die punching arrow edge must be checked and adjusted to prevent the blade gap from being distorted when the mold is loaded and unloaded during transportation.

(3)    Before setting the precision carbide mould, clean the upper and lower surfaces of the mold to ensure that the mold mounting surface and the working table surface of the punch are crushed and the parallelism of the upper and lower mounting surfaces of the mold during production.

(4)    The work surface of the punch press must be parallel to the bottom surface of the slider, and the deviation of parallelism should be less than 0.03

(5)    After the carbide mold is set up, open the mold and clean all parts of the mold, especially the guide mechanism. For the surface part (appearance part), the mold surface is clean and clean to ensure the quality of the part. Slide each mold carry out lubrication and inspection of various parts of the mold, especially safety parts (such as punching waste holes, etc.).

(6)    After the sample is flushed out, it must be confirmed immediately whether it conforms to the product specifications.


2. Maintenance in production:

(1)    When the carbide mold is used, the guide post and guide sleeve should be lubricated regularly.

(2)    Lubricating oil or stamping oil should be added to the corresponding parts and cutting edges of the mold regularly during production

(3)    Double-material punching and shearing are strictly prohibited, and other items except stamping materials and lubricating oil should be kept away from the working area.

(4)    The iron powder in the cutting edge should not stay too much, and the remnants should be treated in time and the waste should be cleaned up regularly. After the production, the mold should be comprehensively inspected and cleaned to ensure the cleanliness of the cemented carbide mold.


3. Maintenance of molds after use:

(1)    The cutting edge of cemented carbide mold must be sharpened after a long time of use. After grinding, the cutting edge surface must be demagnetized and must not be magnetized, otherwise it is easy to cause blockage.

(2)    Springs and other elastic parts are most vulnerable to damage during use, and usually break and deform. The method adopted is to replace it. In the process of replacement, you must pay attention to the specification and model of the spring. The specification and model of the spring are confirmed by the color, outer diameter and length of the three items. Only when the three items are the same can they be replaced.

(3)    The punch is prone to breakage, bending and gnawing during the use of the precision carbide mould, and the punch sleeve is generally gnawed. Damaged punches and sleeves are generally replaced with parts of the same specification. The parameters of the punch mainly include the size of the working part, the size of the installation part, and the length.

(4)    Fasten the parts and check whether the fastening parts are loose or damaged. The method adopted is to replace the parts with the same specifications.

(5)    Material pressure parts such as material pressure plates, uniglue, etc., discharge parts such as stripper plates, pneumatic ejectors, etc. During maintenance, check the relationship between parts of each part and whether there is damage, repair the damaged part, check whether there is air leakage by pneumatic jacking, and take measures for specific conditions. Replace if the trachea is damaged.

 

In order to ensure the integrity of the cemented carbide mould, the production of cemented carbide mould should be very fine, so its production process is more complex, so it is necessary to take good care of the precision carbide mould, in order to prevent wear.

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