Research On Wear Resistence And Microstructure Of ZTA/high Chromium Cast Iron Matrix Composites

ZTA ceramic/high-chromium cast iron composite material combines characteristics of two materials,which reduce product costs and improve product performance.The composite materials have academic research value and meet the needs of industrial production.In this experiment,ZTA particles,high-chromium cast iron,Cu powder,Ti powder,Cu₇₅Ti₂₅alloy powder and 1Cr18Ni9Ti alloy powder were used as raw materials.Preparation and analyzing the phase interface of ZTA ceramic/high-chromium cast iron composites and the overall wear characteristics of composites with the electric box furnace,the planetary ball mill,the metallographic microscope,the scanning electron microscope and the three-body abrasive wear tester,etc.The research results show that the high porosity ZTA ceramic preform can be successfully prepared by different binders without sintering.While the porosity reached 38%,the preform withstood thermal shock in casting process.By using the concept of welding and the technology of the expendable casting process,ZTA/high chromium cast iron composites with excellent properties were successfully prepared.According to observe the microstructure of the composite interface and analyze its composition,it was found that the ceramic particles are completely encapsulated by the high-chromium cast iron,and a metal binder was connected between the two interfaces to improve the combination.It was found that the effect of different metal powders as binders is different,and the affinity and wettability of different elements for metals and ceramics are different.It was found that the wettability of Cu and Ti for ceramics is good,and they easily migrate and accumulate at the interface.During the casting process,Cr and Ni will dissolve into the high-chromium cast iron matrix.It was found that during the sintering process,Ni,migrating into the high-chromium cast iron matrix,promotes the migration of Ti,improving the wettability of the ZTA ceramic metal interface,and makes it accumulate to the phase interface.While the tri-body abrasive wear condition is similar with the actual operating conditions,choosing ZTA?20%ZrO2?,comparing the effect of different content of metal binder on the wettability of ceramic and high-chromium cast iron,the metal binder content is too small The ceramic interface is fully wrapped and the ceramic is in direct contact with the high-chromium cast iron and is prone to defects.With increasing content of 1Cr18Ni9Ti,wear resistance increased.When the content of 1Cr18Ni9Ti was 12%,the wear resistance of the composites performed best.However,if the content of the metal powder is further increased,the amount of the binder used in the preparation of the preform have to increased.In the casting process,the binder,such as water glass,remained and formed hard and brittle phase at the interface to causes performance degradation.When the content of Cu₇₅Ti₂₅ was 12%,the wear resistance of the binder composite material was the best.It was found that a transition layer was formed between the interface of the composite material,and binders and high-chromium cast iron completely wrap around ZTA particles.The two exhibited metallurgical bonding and high interfacial bonding strength,which improved the wear resistance and service life of the composite as a whole.Comparing the metal powder binders of different compositions,designing comparative samples with different contents and according to the amount of wear of composite materials and the high chromium cast iron standard specimen,the relationship between the composition,content and wear resistance of the materials were judged.The wear and failure of the composite material includes the high-chromium cast iron base is mainly a cutting furrow,and the ceramic is mainly subjected to fatigue spalling.The reinforcements is to enhance the protection of the substrate,i.e.,the"shadow effect",and the buffering effect of the matrix on the impact of reinforcements,i.e.,the"support effect."...