Mould Heat-treatment technology analysis

Hits: Date:2011-9-22 Font Size:14px 12px
Mold heat treatment is to guarantee the performance of the mould process of mould, important the manufacturing precision mould, the strength of the mold, the working life, mould manufacturing cost has a direct impact. Since the 1980 s, the international mold heat treatment technology of fast development of vacuum heat treatment technology, field is the mould surface strengthening technology and die material hardening of the technology.
Mould c technology
Vacuum heat treatment technology is developed in recent years of a new type of heat treatment technology, it has the characteristics of mould manufacturing, it is urgent need, such as prevent oxidation heating and decarbonization; the vacuum takes off gas or in addition to, eliminate gas hydrogen brittleness, so as to improve the material (parts) of plastic, toughness and fatigue strength. Vacuum heating slowly, parts inside and outside factors such as temperature, smaller decided the vacuum heat treatment process of part deformation caused by small, etc.
Vacuum heat treatment is mainly used in the mold of cold hardening, vacuum is oil quenching and tempering vacuum air vacuum. To maintain the workpiece (such as mould) vacuum heating, the excellent characteristics of coolant and cooling process selection and make is very important, die quenching process is primarily by oil and cold air. After heat treatment for mechanical processing mould no longer working hardening, use as far as possible, especially the vacuum quenching vacuum tempering the workpiece (die), it can improve the surface quality and the mechanical properties of the related, such as fatigue properties and surface brightness, corrosion resistance, etc.
Heat treatment process of the success of the computer simulation technology development and application, make the mould intelligent heat treatment possible. Due to the small batch production mold (even the piece), many kinds of heat treatment, and the characteristics of high performance requirements and not allowed to appear the characteristics of waste, and make the mould intelligent heat treatment must be. Foreign industrial developed countries such as the United States, Japan, in high-pressure gas quenching vacuum, development is soon, mainly for the target is also die.
Mould surface treatment technology
Mould in the work besides the requirement with a high enough matrix strength and toughness with the reasonable, the surface of the performance of die working performance and service life is very important. Mould surface treatment technology, is through the surface coating, surface modification or composite processing technology, change, the shape of the mould surface chemical composition, organization structure and stress state, in order to have the surface properties of the system engineering. At present in the mold for application in the more mainly is the permeability nitrogen, carburizing and hardening film deposition.
Because nitrogen technology can form good permeability performance of the surface, and permeability nitrogen technology and the steel quenching process has the good coordination, and permeability nitrogen low temperature, permeability nitrogen cooling, after fierce does not need to die of deformation of the tiny, so the mould surface strengthening is the permeability nitrogen earlier, also is the technology of the most widely applied.
Mould carburizing is in order to improve the overall strong toughness, die mold working surface is of great strength and wear resistance. Hardening film deposition technology is more mature is CVD, PVD. Mould since the 80 s the coating sclerosis membrane technology. The current technology conditions, hardening film deposition techniques (mainly equipment) the high cost, still only in some precision, long life die on the application, if the heat treatment center set up the way, is the cost of film coated with sclerosis will reduce the, more mould if the this skill, can improve the overall level of mould manufacturing in China.
Die material hardening of the technology
Since the 70 s, the international on proposed the hardening of the idea, but because processing machine stiffness and cutting tool restriction, the hardening of the hardness cannot reach the use of mold hardness, so the hardening r&d investment in the technology is not big. Along with the machine tools and the improvement of the performance of the cutting tool, die material hardening of the technology development speed, to the 80 s of the last century, the international on developed countries in plastic die material use on the proportion of hardening module has reached to 30% (currently in above 60%).
Our country in the mold of hardening technology advance materials, late start, small, is still cannot meet the requirements of domestic mould manufacturing. Using the hardening mould material, can simplify the mould manufacturing process, shorten the mould manufacturing cycle, improve the mould manufacturing precision. Can foresee, along with the progress of the processing technology, the hardening die materials will be used for more mold type.