Influence Of Nickel And Tin On The Microstructure And Performance Of Fe-based Matrixes For Diamond Tools

Diamond tools are widely used in construction industry,materials industry,optical processing,ceramic modification,geological drilling,electronic and other fields.Diamond tools need better property in modern manufacturing.Artificial diamonds are mostly in the form of micro-powder or small particles.The excellent properties of the matrix material can be achieved by the connection of the matrix material.The excellent properties of the matrix material can be achieved by the connection of the matrix mat erial.In this paper,Ni,Sn elements were added to Fe-based matrix,then microstructure evolution of the matrix was studied.Ni,Sn elements were added to Fe-Cu matrix,and the influence of content of elements on its microstructure and performance was analyzed.The FeCuSnNi matrixs were prepared and their microstructures and properties were analyzed.The interaction function of elements in the matrix was analyzed.The effect of matrix composition on hardness and bending strength was studied by regression model.The main conclusions are as follows.There is almost no diffusion between theα-Fe powder and theα-Fe/Ni powder,when sintered temperature is 530℃.The structure of sintered matrix are mainlyα-Fe phase and Ni-based solid solution.The structure of sintered matrix are mainlyα-Fe phase and Ni-based solid solution,when sintered temperature is 760℃or 800℃.At the Fe/Ni interface,diffusion velocity of the element is rapidly along the surface and the crystal boundary.Then the structure of the interface is mixture of small blockα-Fe andγ（Fe,Ni）solid solution.Because of small negative value of enthalpy of FeNi3 compound formation,The solid solution ofγ（Fe,Ni）is formed in the Fe-Ni sintering system but not the Fe/Ni intermetallic compounds.When sintered temperature is 530℃,Fe atoms dissolute and diffuse into liquid tin phase in the sintering process,and FeSn compounds is formed.When the content of tin is low,the liquid Sn completely reacts to FeSn compounds.The matrix containsα-Fe phase and FeSn compound after sintering.When the content of tin is high,there are liquid phase residues at the end of sintering process.The liquid tin phase and FeSn 2 compounds react to FeSn compounds at the temperature-fall period.The matrix containsα-Fe phase and FeSn compound after sintering.The reaction rate of FeSn compounds was accelerated when sintered temperature is 620℃.The liquid tin and Fe completely reacts to FeSn compounds in sintering process.The matrix containsα-Fe phase and FeSn compound after sintering.The Fe3Sn2 compound is generated while Sn diffuses into Fe to form a solid solution at the same time.The velocity of solid diffusion is quick at 760℃.When the content of tin is low,few Fe3Sn2 compound is completely consumed.The sintered matrix containsα-Fe phase and（Fe,Sn）solid solution.When the content of tin is higher,The sintered matrix containsα-Fe phase,（Fe,Sn）solid solution and Fe₃Sn₂ compound.The Fe3Sn compound is generated while Sn diffuses into Fe to form a solid solut ion at 800℃.When the Sn content is low,the Fe3Sn compound is consumed completely.The sintered matrix containsα-Fe phase and（Fe,Sn）solid solution.There are residual liquid tin in the system at the end of sintering process.The sintered matrix containsα-Fe phase,（Fe,Sn）solid solution,less FeSn and FeSn2 compound.The structure of FeCuNi sintered matrix mainly containα-Fe phase,Cu-based solid solution andγ（Fe,Ni）phase.The result of element interaction theory shows that Ni tends to form solid solution with Fe and Cu,it conform with the experiments.With the increase of Ni content,The increase ofγ（Fe,Ni）and Cu-based solid solution in the structure produces solid solution reinforcement.The hardness of the matrix increases with the increase of Ni content.There is no significant change in matrix.The atom on the contact surface of Fe in contact with Ni diffuses faster on the surface and the crystal boundary.At the Fe/Ni interface,diffusion velocity of the element is rapidly along the surface and the crystal boundary.Then the structure of the interface is mixture of small blockα-Fe andγ（Fe,Ni）solid solution.The structure of FeCuSn sintered matrix mainly containα-Fe phase,Cu_13.7Sn solid solution and Cu3Sn compound.With the increasing of Sn content,the content of Cu13.7Sn solid solution decrease and the content of Cu3Sn compound increase.The matrix mainly contentα-Fe phase and Cu3Sn compound.The theoretical calculation of bond parameters and the results of experiment are well-matched.When the content of tin is 5 wt.%,the liquid phase is sufficient to fill the porosity of the powder the sintered system.Therefore,there is no significant change of the matrix with the change of Sn content.With the conten t of tin increasing,the content of Cu3Sn compounds which is hard and brittle increases,so the hardness of the matrix increases.Cracks tend to spread within the compound and along the phase boundary between the compound andα-Fe phase.The bending strength decreases with the increase of Sn content.The mixture experiment of FeCuSnNi matrix was carried out by extreme vertices design method.Regression model was used to predict the hardness and bending strength of the matrix.The predicted value which calculated by regression equation is basically matched with the experimental value.The FeCuSnNi matrix with different components mainly contain Fe-based solid solution,γ（Fe,Ni）solid solution,Cu_13.7Sn solid solution,and Cu3Sn compound phases.The cracks in the matrix originated from the Cu3Sn compound,and then extending in compounds or along the phase boundary of the Cu 3Sn compound andγ（Fe,Ni）solid solution.Cu_13.7Sn solid solution can hinder propagation of crack.The higher the Sn content,the more Cu3Sn compounds in the matix,and the hardness it is.But the brittle phase cuts off the matrix,the bending strength of the matrix decreased.Ni element tends to soluble in Cu and Fe,so it can reinforce the matrix.The hardness and bending strength of the matrix are improved with the increasing of Ni content.Cu element tends to react with Sn to form Cu3Sn compound.When Sn content is low and Cu content is high,the amount of Cu solid solution is high,so the hardness is reduced.When the Sn content is high,there are a mass of brittle phases,so the hardness of matrix do not change with the iscreasing of Cu content.Cu element tends to form a permutation solid solution with Ni and Fe to produce solid solution reinforcement.the bending strength of the matrix rise with the increase of Cu content.