Research On Impact Abrasive Wear Resistance And Hardening Behavior Of ZTAp Reinforced High Manganese Steel Composite

Impact abrasive wear is a very common form of wear loss in the fields of excavation,mining,and processing.High manganese steel is a class of wear-resistant material widely used in the field of impact abrasion wear,however,the engineering practice effect found that conventional high manganese steel still has insufficient wear resistance due to its insufficient ability to produce work-hardening at the early stage of use or under other conditions such as low impact energy.At present,ceramic/steel matrix wear-resistant composites with high hardness and high modulus have been widely used in mining and processing,etc.,and have achieved good economic benefits.Among them,ZTA（Zr O₂-toughened Al₂O₃）ceramic particles have been extensively studied and used because of their excellent overall properties such as high hardness,phase transition toughening,and high-temperature resistance.In this study,large-size ZTA ceramic particles reinforced with high manganese steel matrix wear-resistant composites with simple process and stable properties were prepared by gravity non-pressure infiltration casting method,which overcame the difficulties of infiltration casting between millimeter-size ZTA ceramic particles and high manganese steel,many casting defects and high preparation cost all along.The microstructure and mechanical properties of the composites were investigated using various microscopic characterization techniques such as SEM,XRD,nanoindentation,EPMA,and EBSD.Meanwhile,the impact wear properties of the composites under different impact work and the mechanical behavior under dynamic compression at high strain rates were investigated.In conclusion,this study was conducted based on the composites under actual production requirements,which is of great practical significance for the development and use of new ceramic/steel matrix wear-resistant composites.The main results of this paper are as follows:（1）Large-size ZTAp/high-manganese steel composites were successfully prepared by infiltration casting method,which solved the long-standing problems of difficult infiltration casting and many casting defects between millimeter-scale ZTAp and high manganese steel matrix.In addition,it was also demonstrated that the prepared composites were structurally complete,without casting defects such as particle shedding and incomposite generation,and the ZTA particles were uniformly distributed in the matrix with a volume fraction of 55.3%.（2）The ZTAp/high manganese steel composite formed the amorphous phase（6₄4）₄ in the interfacial layer during the solidification process,and the micromechanical properties of the composite showed that the nano hardness of the interfacial layer was 6 GPa,which was slightly higher than that of the matrix and much lower than that of the ZTA particles,and Young’s modulus was 200 GPa,which was significantly lower than that of the matrix and ZTA,and the interfacial layer could alleviate the uneven plastic deformation between the ZTA particles and the matrix.The interface layer can alleviate the uneven plastic deformation between ZTA particles and matrix.（3）For the same impact energy,the volume wear loss of both the composite and the high manganese steel matrix increased with time.For different impact energy,the volume wear loss of the composite increases with larger impact energy,while the volume loss of the matrix does not change significantly.The relative wear resistance of the composites gradually decreased when the impact energy is in the range of 2～5J,which was 2.17～0.59 times that of the matrix,respectively.In addition,the work-hardening ability of the composites is lower than that of the matrix,and the depth of the hardened layer increases with the increase of the impact energy.（4）At low-impact energy,the wear mechanism of the composites is mainly based on slight cracking within the ZTA,matrix cutting,wedge formation,and fatigue spalling.At high-impact energy,the wear mechanism is mainly dominated by the shedding of ZTA particles and plowing of the matrix.（5）At different strain rates,the yield and compression strengths of the composites increase with increasing strain rates.Meanwhile,the work-hardening phenomenon of the composites became more obvious with increasing strain rate,and the work-hardening rate increased by more than 2.7 times when the strain rate increased from975s^-1 to 3139s^-1.In addition,the adiabatic temperature rise temperature of the composites gradually increased with increasing strain rate,from 322 K to 600 K when the strain rate increased from 975 s^-1 to 3193 s^-1.