Initially by the European surface technology leader Mr. Kang barr chass in 2004 released by the pulse plasma diffusion (PPD TM) technology, provides large mold manufacturers with a durable, cost-effective and environmentally friendly mould hardening protection scheme. After eight years in the automotive manufacturers (such as BMW, kia, Renault) the successful application of this technology will be in a larger area for commercial operation, cleaning and surface treatment of the die to synthesize into a process. Phil Read, Mr. Kang barr chass PPD TM explained, head of sales and business development.
In December 2012, the headquarters is located in Liechtenstein Europe rui kang barr chass unveiled its new generation of PPD TM technology, its unique processing technology created especially for large forming dies hard, durable and clean surface. Due to the high degree of automation, improve the energy efficiency, cleaning and treatment processing will take place in the same furnace chamber. The technology is already mature and can be a wider range of application. So a new generation of PPD TM technology will become a new industry standard, and are ready to replace the existing serious pollution to the environment of chrome plated,better for the environment
Now in general use in big mould surface treatment is chrome plating technology, use of highly hazardous substances hexavalent chromium. In the process of use and handling of safety, effects and challenges, and will eventually be added to the cost of production. PPD TM technology only need hydrogen, nitrogen and power, and does not produce or use or harmful gases or chemicals. A direct advantage, is in the surface treatment process without chromium compounds, there was no chance whatever of hexavalent chromium particles embedded into production so as to endanger the production line and its nearby workers health.
Figure 1: auto mould cases treated with PPDTM
Ion nitriding of reuse: the cleaning and surface treatment
Nitriding as a technology has been widely used in nearly a century. From the 20 s of the 20th century, the influence of nitrogen on the steel surface is a systemic research. Since the 20th century 60 s, nitriding has become alternative chrome plating technology. Nitriding process is the most important advantage of low temperature treatment can minimize the risk of mold deformation.
The traditional nitriding in the pretreatment stage, however, there is still a problem. Most of the die is cast iron manufacturers. Used in the production process of oil and lubricating oil, which absorbs the cast iron. Before the traditional nitriding process, mould must be clean or in a big stove for minimum of 450 degrees degassing treatment. Such a big stove is difficult to control the temperature and will eventually in the mold surface residual crude oxide layer. The feature of a car, however, need to be very smooth and clean surface. Also, for such a big stove temperature control error will also hurt large car body model. If processing mould uneven temperature, thermal stress will be induced by great temperature TiDuCha resulting in a series of risk of mold damage.
PPDTMtechnology by adding cleaning process in the vacuum furnace and nitriding process itself, to overcome the difficulties in pretreatment. PPDTMhigh-frequency plasma impulse in the nitrogen at a speed of 500000 times a second to spread to the mold, so the mould on the residual oil will not affect the whole process. In the past, this process can only be proved from the theory, the success of the PPDTMtechnology is to clean and in the same place, the same vacuum nitriding furnace. Mold surface oxidation of no risk, also can get more precise temperature control so as to avoid the risk of mold due to thermal stress damage. This continuous vacuum environment created a very clean smooth surface, and for the sheet metal provides an excellent drawing conditions.
Figure 2: the PPD can be widely applied to a large number of cast iron,
cast steel extremely variant.
High-energy pulse plasma generator also has a automatic security control system to ensure the safety of the process of precise control and mould. , in the process of nitriding temperature, pulse interval, voltage and gas composition are very precise control in the set value, and ultimately ensure that greatly enhance die wear resistance and corrosion resistance.
Stop line of time to a minimum will use a lot of automation in modern automation press line mold to large sheet metal drawing, punching and forming into the car. Each set of the mould, as a set of doors or a hood mold, can produce every year more than 200000 of these parts. Each set of special mould according to the different specifications, most can be up to 40 tonnes. Due to the subsequent assembly line requirements for all before continuous seamless splicing, any damaged or missing a set of mould will lead to the entire production line shutdown.
In order to ensure reliable use for a long time, most of the forming die is after surface treatment, the coating or hardening. For a large mold, the standard of surface treatment in the past long-term hexavalent chromium is used to hard chromium plating. However the traditional chrome plated mould service life far less than the coating. So, stamping die in the die life cycle will be due to the die design change or die daily need to be repeated several times chrome plated surface loss (once a year on average).
Chrome plated again not only bring direct costs, and indirect influence. Continuously removed from the production line of mold means producers need more inventory. In the mold to remove the that time, the production is still continue, until the mold back in press line, but the stock is very expensive and requires careful management. By providing lasting high hardness of single process, PPD TM can apparently stamping die covered the whole service life and do not need to surface treatment (about 5 years), which will increase the productivity of nearly 25%.
PPD TM on the surface of the part can also help the mould to reduce maintenance costs, largely due to the spread of the nitrogen make mold surface hardening (rather than just coating), therefore, if the mould is damaged or need to be adjusted, the surface can use oil stone grinding, convex welding or heat treatment, with the high quality surface without conflict. next item: Ion nitriding process quality inspection