| The addition of metal phase makes it difficult to combine the plastic toughness and high temperature stability of ceramic cutting tool material effectively.In order to ensure the excellent comprehensive performance of ceramic cutting tool material,a method of replacing metal phase with intermetallic com pound is proposed.Based on the design principle of ceramic cutting tool material,the matrix phase of ceramic cutting tool material is Al2O3 and the strengthening phase is Ti B 2.The intermetallic compound Ni3Al is selected to replace the metal phase,and Al2O3/Ti B2/Ni3Al?ABN?ceramic cutting tool material is prepared by reaction sintering?Ni/25at.%Al?.Al2O3/Ti B2/Ni3Al?ABNA?ceramic tool material was prepared by direct sintering with Ni3Al.The Physical and chemical compatibility analysis of th e material system shows that there is good chemical compatibility and physical compatibility between the main phases,and the chemical reaction between some raw materials is needed in this project.Al2O3/Ti B2/Ni3Al ceramic tool material was sintered and pr epared,and the effects of different component distribution ratio and preparation methods on its mechanical properties and microstructure were studied.The mechanical properties and microstructure of ceramic cutting tool materials were tested,and the results showed that ABN and ABNA ceramic cutting tool materials prepared by different methods showed similar variation trend in mechanical properties.With the increase of bonding phase,the flexural strength,fracture toughness and density of the material increase gradually,while vickers hardness decreases gradually.The bending strength,fracture toughness,Hardness and density of ABN4 ceramic tool materia ls were 1242.84MPa,13.02MPa·m1/2,16.03GPa and 99.37%,respectively,and those of ABNA4 ceramic tool materials were 1156.13M Pa,15.98MPa·m1/2,15.55GPa and99.38%,respectively.Compared with LP1 tool material with the same matrix and reinforcement,the bending strength and fracture toughness of ABN4 and ABNA4 are improved by 55.36%and 150.38%,44.52%and 206.92%,respectively.The bonding phase of the material effectively fills the gap between the matrix and the reinforcing phase,and the grain does not grow abnormally.With the increase of the content of the binding phase,the grain was refined to a certain extent,and the fracture behavior was mainly along the grain,with a large number of grain pull-out and crack deflection.The friction and wear tests of ABN ceramic tool materials were carried out to study the effects of different grinding materials,speeds and loads on their friction and wear properties.The results show that when ABN and ABNA ceramic tool materials grind Si3N4 balls,the average friction coefficient and wear rate of samples increase gradually,and the wear mechanism is mainly abrasive wear.When grinding GCr15 bearing steel balls,the average friction coefficients of ABN and ABNA ceramic tool materials are reversed,and the wear rate changes are consistent.The wear mechanism of abrasive wear and adhesive wear.There is an order of magnitude difference in wear rate between the two materials for grinding Si 3N4 ball and GCr15bearing steel ball,showing excellent friction and wear p erformance for grinding GCr15 bearing steel ball.The influence of rotational speed on the friction and wear performance of ABN1 and ABNA3 ceramic tool materials is greater than the load.The average friction coefficient of ABN1 ceramic tool materials is t he lowest at600r/min.The wear rate is the lowest at 400r/min.ABNA3 ceramic tool material shows the best friction and wear performance at 600r/min and 50N. |
PDF Full Text Request