3D Metal Printing Technology
In present Metal 3D printing technology is becoming the key technology of intelligent mold manufacturing.
Metal 3D printing is the most representative material-increasing manufacturing technology, and its engineering application helps to improve the digital and intelligent design and manufacturing level of complex precision molds. Unlike traditional machining of metal materials, Metal 3D printing can make complex objects without restriction.
Adding material manufacturing is a technology that uses the method of gradual accumulation of materials to make solid parts or products. Because the increasing material manufacturing technology can quickly produce workpieces and products of any shape without complex tooling and multi-channel processing technology, it has made rapid development in technology research and development and industrial application in the past 30 years.
Therefore, it has become one of the three basic material processing technologies juxtaposed with reduced material manufacturing (mainly cutting) and equal material manufacturing (mainly die forming). Increased material manufacturing, especially the realization of all-digital 3D printing technology, through parts or machine 3D printing design and 3D printing manufacturing to reduce the number of parts, reduce quality, reduce assembly, and produce high-complexity parts.
Metal 3D printing has established a relatively complete industrial chain.
In the 1980s, 3D printing has developed commercial technology, but the initial printing materials are mainly non-metallic materials, so 3D printing is mainly used in the manufacture of models, handicrafts, packaging, medical devices and other non-metallic materials.
In the 21st century, metal 3D printing technology has developed rapidly, and the preparation technology of metal powder is becoming more and more mature. the engineering application of 3D printing technology extends from the initial product development, prototype manufacturing, jewelry, dental and packaging manufacturing to various fields of precision forming in product manufacturing, and has become the most competitive manufacturing means for special complex parts and highly personalized products.
Among them, the 3D printing equipment and corresponding layered software of German EOS, American 3D System and other companies once led the development of 3D printing technology. At the same time, all kinds of consumables used for 3D printing, such as non-metallic materials (nylon, ceramics, etc.), metal materials (stainless steel, tool steel, heat-resistant alloy, aluminum alloy, copper, etc.) powder R & D, production and supply have gradually realized industrialization and commercialization.
However, at present, there are few varieties of metal 3D printing consumables, the price is on the high side, coupled with the large investment in printing equipment and relatively low printing efficiency, at present, the scope of engineering application is mainly concentrated in aerospace, artificial joints (including teeth) and other non-market-oriented products and special industrial and mold manufacturing industries.
Among the metal 3D printing technology, powder bed fusion technology is the most commonly used technology in engineering at present. The printing heat source, one of the key technologies, generally uses laser beam or high-energy electron beam. Laser heat source can be used for laser cladding and selective laser sintering, while high energy electron beam is mainly used for electron beam melting.
Due to the different propagation modes of laser and electron beam in the processing space, the working environment of laser 3D printing is different-laser 3D printing is carried out in air or inert gas (such as nitrogen). The environment of electron beam 3D printing requires a high degree of vacuum to reduce the energy loss caused by electron beam collisions with gas molecules before reaching work. At present, these two kinds of metal 3D printing equipment have established R & D design and production supply system.
Another key technology of metal 3D printing is the preparation of printing materials. The powder bed fusion technology requires continuous uniform laying of metal powder. therefore, the shape of the powder should be spherical as far as possible, which is conducive to the smooth flow of the powder. at the same time, the particle and composition uniformity of the powder should meet the design requirements of the material.
At present, the preparation technology of low-carbon stainless steel, superalloy, titanium alloy, aluminum, copper and other metal powder is more mature, and the variety is rich. For the tool and die steel powder with high carbon content, the burning loss of carbon needs to be controlled in the preparation and use (melting), which affects the performance of printed products, so the variety of tool steel powder is less and the price is higher.
Metal 3D printing technology has been successfully applied in the field of mold manufacturing.
Mold is an important basic process equipment in product manufacturing industry, which has complex structure, high manufacturing precision, harsh working conditions, high reliability and high life requirements. At present, most mold materials are made of metal (more than 90%), of which 90% are iron and steel. In order to complete the manufacturing of complex moulds with high efficiency and high precision, the mold industry is always exploring various new processing methods and manufacturing technology.
But even so, the level of processing technology in the 20th century still can not meet the needs of the rapid improvement of mold design accuracy caused by the progress of digital design technology. as a result, many advanced design schemes can not be realized or forced to reduce manufacturing accuracy due to machining technology. For example, in the cooling system of injection mold for precision and complex plastic products, the local deformation of the part is larger because the machining technology is difficult to process the conformal cooling channel designed by CAE.
Since the beginning of the 21st century, with the breakthroughs of key technologies such as laser power, spot focusing and mold steel powder, the engineering application of metal 3D printing technology in the production of conformal cooling channel of injection mold has been realized. For large and complex injection parts, through the analysis of simulation software, the cross section shape and direction of the channel are designed, and the conformal channel insert is made by 3D printing technology, which is inserted into the mold matrix processed by cutting. The two parts of the cooling channel are connected with hoses on the outside of the die.
This kind of composite manufacturing technology not only avoids the weakness of 3D printing technology such as high powder price and low printing efficiency of die steel, but also solves the problem of unreasonable local cooling of traditional cooling channel. For the small precision structural parts injection mold, the following cooling channel is optimized by CAD and CAE software, and the whole mold is printed directly by metal 3D printing technology.
Metal 3D Printing Technology helps Intelligent Design and manufacture of Mould.
Die forming is a precise and efficient processing method of parts (products), and the design and manufacture of dies has the typical characteristics of “multi-variety, small batch” (single-piece production in most cases). The metal 3D printing technology happens to have an indisputable advantage in meeting the needs of highly personalized high-end customers, and has a high degree of matching with the industrial characteristics of the mold manufacturing industry. It provides a new technology for high-efficiency and high-precision mold processing.
The innovative development of metal 3D printing technology has promoted the improvement of the degree of freedom of digital collaborative design of parts (products) from product development, forming process design and die design. and by comparing the shape control and control effects of various forming schemes in virtual space, we can complete the design of high precision and high efficiency die forming scheme and innovate the whole process of die design and manufacture.
The engineering application of metal 3D printing technology helps to improve the level of digital, networked and intelligent design and manufacturing of complex precision moulds or mold parts, and is becoming a new key technology for efficient and high-precision mold manufacturing.
Article Source : WAYKEN RAPID MANUFACTURING
Image Source : WAYKEN RAPID MANUFACTURING