Progress in Surface Modification Technology

   

 With the development of scientific and technological progress and the edge of science and technology areas covered surface modification technology "vacuum c​oating" continues to extend and expand. Traditional carburizing, nitriding and other chemical treatment technology has become a fundamental part of surface modification technologies; ion implantation technology, laser and electron beam technology in surface modification of materials, for parts of the surface hardening and surface alloying offers new technology and methods.

(1) Salt Nitrocarburizing technology (TUFFTRIDE QPQ). TUFFTRIDE QPQ process is the part after a simple pre-washed and pre-heated to the air after 350 ~ 400 ℃, the alkali cyanate tank for Nitrocarburizing usually treatment temperature is 580 ℃, maintain 60 ~ 120min, special when the case can be reduced or elevated temperatures. Cold treatment using an oxidation at the cooling tank, at a temperature range of 350 ~ 400 ℃ cooling, followed by hot water jet cleaning of the workpiece. In addition to cooling slowly cooling oxidation, good for dimensionally stable parts, but also has the following advantages:

① significantly improved the corrosion resistance of parts;

② parts of the surface in the base product to produce cyanate tank oxide film;

③ better sliding properties.

(2) ion nitriding "multi-arc ion vacuum coating"gas phase analysis and application. In the plasma nitriding process, in addition to temperature and time, furnace gas composition is an important factor in determining the quality of the nitrided layer. Element N, H ratio changes significantly affect the structure of the compound, and the influence of hardness of the diffusion layer to some extent. In addition, the ion nitrocarburizing process, the compound layer is a dense, e single-phase layer can form, furnace gas composition is a decisive factor. Typically by controlling the furnace atmosphere into the nitriding furnace gas flow rate is set, but the actual flow rates at different points of the same partial pressure of the gas is often quite different, resulting in factors such differences are: from gas means a chemical reaction to occur at gas path characteristic nitriding furnace, the speed of change and the like inflatable gas ions between different conditions and the like.