Effect Of Coating On Abrasion Resistance Of Materials Under Different Particle Size Conditions

The problem of hydraulic mechanical abrasion is inevitable.The fragile ecological environment and the river sediment let the hydraulic mechanical abrasion problem become particularly acute in China.The hydraulic mechanical abrasion lead the economic losses immeasurable every year.Based on the above reasons,four materials of 16Mn?45#?ZG20Si Mn and type a high manganese steel which often used in hydraulic mechanical are used to experimental research under difference sand sizes and explored the damage rule of abrasive and failure modes on sand size;At the same time,the four kinds of materials are tested on the same sand particle sizes by sparying alumina?Al₂O₃??nickel base alloy?Ni60??tungsten carbide?WC??tungsten cobalt chromium?CoCrW?respectively.The experiment results showed that:?1?For the four kinds of materials,the result showed a linear relationship between total abrasion weightlessness and test time when the sand sizes are less than 0.349 mm at the same experimental conditions,on the contrary the result showed a gaussian function of nonlinear increase between total abrasion weightlessness and test time when the sand sizes is not less than 0.349 mm.?2?The specimen surface of materials are mainly destoried by vertical impact wear and cavitation erosion,no obvious horizontal cutting wear and tear,when the sand size is 0.043 mm.In the other groups,the abrasion failure of the surface of the specimens is mainly combined with the cutting wear and cavitation damage in the horizontal direction,at the same time with a certain amount of vertical impact wear.?3?The abrasion resistance of steel 45 is relatively good,16 Mn and ZG20 Si Mn are relatively minor,the undissolved type a high manganese steel plate is relatively poor.?4?The higher hardness of Al₂O₃ ceramic coating have strong wear resistance,but the bonding strength between coating and matrix is not high,so that the coating porosity is too large.In this case,the coating will appear fall off and lead failure to have abrasion resistant effect in the process of impacting wear,so the Al₂O₃ ceramic coating is not applicable to non-contact impact wear.?5?Coating of WC has a2 good anti-wear effect,however it is so easy arise phase change and produce W2 C and W.This factors lead to crack of grain boundary and cause weight loss under the impact of sands contained stream flow in high speed.In this test the weight loss of WC coating greater than that of without spraying wear-resistant coating matrix specimen.?6?The bonding strength between Ni60 or CoCrW coating with specimen matrix is good.There are not appear Crack and pit,and the hardness of coating is higher than that of matrix.The coating are not damaged by the flow with the sand in high speed,so they have a good Abrasion resistance.It is obvious that the abrasion resistance of CoCrW coating is the best,so that it can reduce the abrasion weight loss of the materials to half and greatly improve the abrasion resistance of equipment to extend the service life by using CoCrW coating.