Research And Application On The Abrasive Wear Resistace Of Bionic Enhanced Working Parts Under High Impact Force

In recent years, the development of China’s cement industry is very fast. It hasbecome the world’s first cement producer. High-pressure roller mill is an importantprocess equipment in cement production. And the key component of the high-pressureroller mill is grinding rolls, which is used for extrusion and grinding raw materialsand the clinker of cement. Wear roller bear a huge impact pressure and wear in thework process. The combined effects of multiple stress superposition made roller’sservice life severely reduced. It is a major technical problems to be solved. It has animportant significance to increase the service life of the roller mill for it reducecement production costs and increase productivity. The commonly used methods inthe actual production to improve the life of the grinding roller is applying one or morewear resistant layers on surface. It is a solution on single factor. However, because ofthis type of mill is working in a extreme environment, the service life extention willgreatly increase the cost.In the millions of years of biological evolution, creatures have to adapt to a varietyof harsh living environment, and evolve some special features. By observing thepangolin, shell and other organism with excellent surface wear properties, theirsurface is non-smooth. According to the research on dragonfly wings and leaves,irregular surface texture and veins vein structure have good resistance to fatigue andcrack. Further studies showed that excellent biological function is the result ofmultiple factors coupled effect.In this paper, the main working parts-grinding rolls-used in cement production ischoosen as the object to study the biological systems. By simulating the couplingprinciple of biological material, shape and structure, the bionic roller was designed.Two kinds of roller were invented. They are rollers with hard particles coated in softmatrix and hard wear resistant layer coated in soft bionic skeleton (both got patentlicense). It enhanced both abrasion and impact resistance without sacrifice anyone. Itsolve the technical problem. The shape of soft matrix and hard particals structure, material factor, the size andspacing, bump height and material composition were systematic researched. Theeffect of abrasive, impact energy, unit bump height on wear results were alsodiscussed. While bionic unit area is fixed, specimen with cylindrical unit has the bestwear resistence. The size of bionic units has little effect on microstructure. Biggerspacing will enlarge the soft area. If the abrasive particles are smaller than the space,it will expend the soft area and increase wear loss. The best spacing is1mm and thebest bump height is0.6mm. While the impact is low, high chromium cast iron is thebest unit material. While the impact is high, sub high chromium cast iron is the best.Nb, WC and TiC can be used as strengthening particles.The hard wear resistance layer and soft tough bionic skeleton coupling structure isresearched. The effect of material, mesh diameter, mesh size and bump height to wearresult under impact are also discussed. Diamond mesh can avoid the wear on skeletonand fixed wear resistance layer. Skeletal mesh diameter ratio will influence the softphase rate. The best percent of it is25%.The results show that hard and soft bionic coupling structure have better wearresistance. Its abrasion mechanism is that bionic coupling structure improve the wearresistance of the original single factor or material into the material, structure, shapeand many factors together. They block the cracks, stress dispersion and absorb stress.It also block the crack expansion into a split source, keep enhance layer from spalling.The additional contact points reduce the contact stress, reduce the impact damage.The soft part is also play a part in absorb the impact. Their functions combinedtogether, makes the wear resistance of bionic specimen increased.The soft and hard coupling structure is also tested in abrasive wear. The results aresimilar to the wear with impact. According to the bionic coupling structure parameters,tests in real production are proformed in Yatai cement company, Tonghua Ltd. Theworking life of bionic roller is extended to twice than before. It’s improved from5300-7600hours to12000-14000hours. Direct economic benefits is about23millionand indirect economic benefits is more than6,000million.