| Cemented carbide is widely used in cutting tools,due to its good thermal strength,red hardness,high toughness and thermal fatigue resistance.However,its oxidation resistance is poor,which can't meet the requirements of modern dry high temperature cutting.The hardness,wear resistance and thermal stability of AlTiSiN and AlTiCrSiN coatings are better than that of cemented carbide.If they are used in dry cutting tools,the protective coating has a great prospect.AlTiSiN and AlTiCrSiN coatings were deposited on YG10X cemented carbide by arc ion plating.YG10X and AlTiSiN(AlTiCrSiN)coated YG10X samples were annealed at different temperatures in a box resistance furnace in atmospheric environment.(1)With the increase of annealing temperature,the wear rate of YG10X cemented carbide first decreases and then increases,and the wear rate of the original sample is 1.28×10-15 m3/Nm?The wear rate of annealed samples at 200?is reduced to 0.68×10-15 m3/Nm?With the increase of annealing temperature,the wear rate of the samples increases sharply,and the wear rate of the annealed samples increases to 4.06×10-15 m3/Nm at 700?.The samples above 800?were basically oxidized,so no friction and wear experiments were carried out.Annealing under 400?did not oxidize the sample,and a little oxide began to appear at 400?.The phase of Co(111)and Co(200)disappeared completely and a large number of oxides appeared at 500?and the main components of the oxides were Co WO4 and WO3.The thickness of oxide scale also increased from17.83?m at 400?to 999.23?m at 700?.(2)The color of the aluminum coating was lighter after annealing at 600?,and XRD results showed that the samples oxidized and Al2O3 was formed.The bonding force of the coating decreases with the increase of annealing temperature.The wear rate shows the trend of rising first and then decreasing,and then rising sharply.The rising turning point appears at 500?.(3)The macro and micro properties of AlTiCrSiN coating after annealing at different temperatures have not changed significantly.The bonding force of the coating decreases with the increase of annealing temperature,especially after annealing at 300?.The average friction coefficient decreased first and then increased and then decreased at last,and reached the maximum at 400?.The wear rate showed a gradual upward trend,and the temperature of 500?was slightly improved,which was the inflection point of the increase of wear rate.(4)The results show that the anti-oxidation and wear resistance of AlTiCrSiN coating are better than that of AlTiSiN coating.But the toughness of AlTiSiN coating is better than that of AlTiCrSiN coating,because Lc1 is not found in the scratch test of AlTiCrSiN coating.At the same time,the protective effect of AlTiCrSiN coating on the matrix is better than that of AlTiSiN coating. |
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