New process of heat treatment and surface treatment

In order to improve the wear resistance, hardness and corrosion resistance of the working surface of the die, a new technology of heat treatment and surface treatment must be adopted, especially the new surface treatment technology. In addition to the surface hardening treatment methods such as hard chromium plating and nitriding, the strengthening technology of mold surface performance has been developing rapidly in recent years, and the practical application(CVD), physical vapor deposition (PVD) and salt bath metal infiltration (TD) are some of the fastest developing and most widely used new technologies for surface coating hardening treatment. They are of great significance for improving the life of dies and reducing the consumption of expensive materials.

In the stamping die, the use of various kinds of metal materials and non-metallic materials, mainly carbon steel, alloy steel, cast iron, cast steel, hard alloy, low melting point alloy, zinc alloy, aluminum bronze, synthetic resin, polyurethane rubber, plastic, laminated birch etc..

The material for making mould requires high hardness, high strength, high wear resistance, proper toughness, high hardenability, no distortion (or less deformation) and no cracking when hardening.

Reasonable selection of die material ans correct heat treatment process are the key to ensure the life of die. Mould for various uses, should be based on the comprehensive consideration of its working condition, stress condition and the machined material properties, production and productivity factors, and the performance of the above requirements has been focused on, and then make the appropriate choice of steel and heat treatment process.

1. Production lot size

When the production quantity of the stamping parts is large, the stamping die, the stamping die parts, the punch and the die should be made of high quality and good wear resistance die steel. As for other parts of the process, structural parts and auxiliary structural parts of the mold, materials should also be improved accordingly. In small quantities, should be appropriate to relax the requirements of material performance, in order to reduce costs.

2. The properties of the stamping material and the conditions for the use of the mold parts.

When the material being pressed is hard or the deformation resistance is great, the convex and concave die of the die should choose the material with good abrasion resistance and high strength. When drawing stainless steel, aluminum bronze die can be used, because it has better adhension resistance. The guide pin bushing requires better wear resistance and better toughness, so the surface carburizing of low carbon steel is adopted. For example, the main weakness of carbon tool steel is hardenability. When the section size of die parts is large, the center hardness is still now after quenching, but.,

Work in the press stroke times, due to its good impact resistance has become advantages. For fixed plates and stripper parts, they should not only have enough strength, but also require small deformation during the working process. In addition, the performance of mold parts can be improved by cold treatment, cryogenic treatment, vacuum treatment and surface strengthening. For the extrusion die punch and die poor working conditions should be selected with cold die steel good enough hardness, strength, toughness, wear resistance and other mechanical properties, and it should have some red hardness and thermal fatigue strength etc..

3. Material properties

The cold and hot properties of the material and the existing conditions of the plant should be taken into account.

4. Reduce production costs

Attention should be paid to the use of micro deformation stamping die steel to reduce machining costs.

5. Develop special die steel

For special requirements of mould, the mould steel with special performance should be develop.

6. To consider the production and use of mould in our country

Selection of stamping die materials should be based on the use of mold parts to determine, so as to meet the main conditions of the premise, the choice of low price materials, reduce costs.

With the rapid development and combination of computer technology, mechanical design and manufacturing technology, a new technology of computer aided design and computer aided manufacturing (CAD/CAM) has been developed.

CAD/CAM is the key technology to reform the traditional mold production mode, is a system engineering of high technology and high efficiency, it is in the form of computer software to provide users with an effective auxiliary tool, the engineering and technical personnel can use the computer to design and optimize the product structure, and mold forming technology, CNC machining and cost etc.. Mold CAD/CAM can significantly shorten the mold design and manufacturing cycle, reduce production costs and improve product quality, has become the consensus of the people.

With the advent of powerful professional software and high integrated manufacturing equipment, based on the 3D modeling, based on Concurrent Engineering (CE) mold CAD/CAM technology is becoming the direction of development, it can realize the design for manufacturing and assembling, and realize the simulation of NC machining process of forming process, the integration of design and manufacturing.

Rapid economic modeling technology in order to meet the need of variety and batch production in industrial production, accelerate the speed of mould manufacturing, reduce the cost of mould production, development and application of rapid economic modeling technology has been paid more and more attention. At present, the rapid economic mold main technology mainly has low melting point alloy mold making technology, zinc based alloy mold making technology, epoxy resin molding technology, spray forming molding technology, laminated steel plate molding technology. The application of rapid economic mold manufacturing technology of mold, can simplify the mould manufacturing process, shorten the manufacturing cycle (than ordinary steel mould manufacturing cycle is shortened to 70%-90%), reduce the cost of mould production (than ordinary steel mould manufacturing cost is reduce from 60% to 80%) has achieved remarkable economic benefits in industrial production. It plays a very important role in improving the development speed of new products and promoting the development of production.

Stamping die profession development present situation and technical trend

First, the status quo

Since the reform and opening to the outside world, with the rapid development of the national economy, the market demand for the mold has been increasing. In recent years, the mold industry has been rapid development in the growth rate of about 15% of all components of the system mold industrial enterprises has undergone tremendous changes, in addition to state-owned professional mold factory, collective, joint ventures and private development has been rapid. With the pace of integration with the international market continues to accelerate, the growing market competition, people have become increasingly aware of the importance of product quality, cost and development capabilities of new products. And mold manufacturing is one of the most basic elements of the chain.

In recent years, many mold enterprises have increased their investment in technology progress, and regarded technological progress as an important driving force for enterprise development. Some domestic enterprises has spread mold of two-dimensional CAD, and started using UG, Pro/Engineer, I-DEAS, Euclid-IS and other international software, individual manufacturers have introduced Moldflow, C-Flow, DYNAFORM, Optris and MAGMASOFT CAE software, designed and successfully applied in stamping die.

The manufacturing technology of large stamping die represented by automobile panel dies has made great progress. Some motor corporation mold factory, FAW mold center and other mold manufacturers have been able to produce part of the car cover die. In addition, many research institutes and universities carry out the research and development of die technology. After years of efforts, in the mold CAD/CAE/CAM technology has made remarkable progress in improving the quality of die and shorten the mold design and manufacturing cycle and so on.

Although China’s mold industry has made remarkable progress in the past more than 10 years, but many aspects still have a big gap compared with the developed countries. For example, the proportion of precision machining equipment in the mold processing equipment is relatively low; CAD/CAE/CAM technology penetration rate is not high; many advanced mold technology application is not wide enough, resulting in a considerable part of s large, precision, complex and long life mold imports.

Two, the future development trend of manufacturing technology in stamping die.

The development of die technology should serve the requirements of mould products such as short delivery time, high precision, good quality and low price.

To achieve this requirement need the following:

(1) The comprehensive promotion of CAD/CAM/CAE Technology.

Die CAD/CAM/CAE technology is the development direction of mold design and manufacture. With the development and progress of microcomputer software, the conditions for popularizing CAD/CAM/CAE technology have been basically mature, and all enterprises will intensify the training of CAD/CAM/CAE technology to be popularized across the region, across the enterprise and across the board. It is possible to integrate the technology resources and make virtual manufacturing possible.

(2) High speed milling;

In recent years the development of high-speed milling in foreign countries, greatly improve the processing efficiency, and get a very high surface finish. In addition, it can also process high hardness modules, and also has the advantages of low temperature rise and small thermal deformation. The development of high speed milling technology has injected new vitality into the manufacture of large cavity mould in the automotive and household electrical appliance industry. At present, it has developed to a higher level of agility, intelligence and integration.

(3) Die scanning and digitizing system

High speed scanner and die scanning system provides many functions in the model of the model or from scan to work, greatly shorten the manufacturing cycle in the development of mold. Some fast scanning system can be quickly installed in existing CNC milling machine and machining center, CAD data to achieve rapid data acquisition and processing program, automatic generation of a variety of different formats of CNC system, reverse engineering for mold manufacturing. Mold scanning system has been successfully applied in automobiles, motorcycles and household appliances, and it is believed that it will play a greater role during the “fifteen” period.

(4) The EDMMILL

Electrical discharge milling (EDM) is also called EDM, which is a new technology to replace the traditional machining cavity with formed electrodes.

It is a high-speed rotation of the tubular electrode for a simple 3D or 2D contour maching (same as CNC milling), it is no longer necessary to create the complex shape of the electrode, which is obviously a major development in the field of edm. Foreign countries have used this technology of machine tools in mold processing applications. The technology is expected to grow.

(5) To improve the standardization of the mold

Standardization of China’s mold is constantly improving, it is estimated that the current standard use of China’s mold parts coverage rate has reached about 30%. Foreign developed countries generally around 80%.

(6) The technology of high-quality material and advanced surface treatment.

It is very necessary to select the high quality steel and apply the corresponding surface treatment technology to improve the service life of the die. Whether the heat treatment and surface treatment of mould can give full play to the material performance of die steel. The direction of heat treatment of die is vacuum heat treatment. In addition to improving the surface treatment of the mold, advanced technologies such as vapor deposition (TiN, TiC, etc.) and plasma spraying should be developed.

(7) Mold polishing automation, intelligent

Have a greater impact on the quality of the mold surface of the die life, the appearance of quality parts, grinding and polishing method of automation and intelligent to replace the existing manual operation, in order to improve the surface quality of the mold is an important development trend.

(8) The development of the mould automatic processing system.

This is the goal of China’s long-term development. The reasonable combination of mould automatic machine processing system should be more than; with accompanying positioning fixture or positioning plate; complete machines, CNC tool library; complete CNC flexible synchronization system; quality monitoring and control system.