Wear and Corrosion Resistance of ZTAp-Fe Composites with Honeycomb Configuration
In order to improve the wear and corrosion problems of mining machinery components,in this paper,honeycomb configu-ration zirconia toughened alumina particle reinforced iron matrix(ZTAp-Fe)composite was prepared,and the composite casting was carried out by casting 30SiMn steel with ZTAp in the proportion of 5％,10％and 15％(mass fraction)of honeycomb precast body.The properties were tested by X-ray diffractometer(XRD),energy spectrum analysis(EDS),scanning electron microscopy(SEM),three-body abrasive wear and corrosion immersion.The results showed that:30SiMn steel was mainly composed of ferrite and pearlite,and the iron matrix organization was mainly α-Fe and intracrystalline precipitation of a diffuse distribution of granular carbides as(Fe,Cr)7C3.Although ZTAp was not surface modified,due to the"cold shrinkage"of the iron matrix during the cooling process and 30SiMn steel solidification process,ZTAp in the composite material was subjected to double compressive stress,and the iron matrix was tight-ly bonded.5％and 10％of ZTAp,the composite material interfacial bonding was good,ZTAp content of 15％,the reinforcing phase particles of the mass was higher than that of the particles,particles and particles are easy to appear with each other(bridging)phenom-enon,and the toughness of the metal matrix space was reduced.At the same time,the thermal conductivity of the particles was lower than that of the iron matrix,and the increase of ZTAp content could easily cause the phenomenon of particle agglomeration,blocking the transfer of casting heat in the composite material,resulting in the reduction of the fixed role of the iron matrix on the ZTAp,the cooling process of the particle aggregation and the tip was easy to produce a concentration of stress,the combined effect of the part of the particles and the matrix between the more obvious pore defects.When the proportion of particles in the composite material in-creased from 5％to 15％,the hardness of the iron matrix regionincreased with the increase in the mass fraction of ZTAp hardness,the effect of reinforcing phase ZTAp on composite materials had been improved,the interfacial hardness of 30SiMn steel and 30SiMn-iron matrix increased first,then fell.The wear volume of ZTAp-Fe composites with honeycomb configuration was much smaller than that of HARDOX450,NM450 and 30SiMn steels,and the incorporation of ZTAp hard phase had a significant effect on the enhancement of the wear resistance of the composites.The abrasion resistance of the composites showed an upward and downward trend with the in-crease of the particle mass ratio in the composites;when the particle mass ratio was 5％,the protective effect on the matrix was weaker than that of the control group due to the lower particle ratio,the surface abrasion marks were deeper,and the abrasion volume was larg-er.When the proportion of particles was 10％,the enhanced particles on the iron matrix protection effect was enhanced,so that the depth of the abrasion mark was reduced,the surface ZTAp in the role of abrasive due to the combination of particles and the iron ma-trix was good,did not appear obvious signs of shedding,wear resistance had been improved.15％of ZTAp,the phenomenon of inter-particle agglomeration was more serious,resulting in a greater number of porosity defects;the defects in the region of the iron matrix could not play a good fixation on the particles in the abrasive process.Iron matrix could not play a good role in fixing the particles in the wear process,at this time,the carrying capacity of the iron matrix was easy to prematurely reach the yield stress and subsequent defor-mation,cracks were easy to produce and expand along the combination of weak surfaces and defects,ultimately leading to premature particles and the iron matrix to fall off,the increase in the wear volume,to summarize the above.When the particles had a mass propor-tion of 10％and aZTAp proportion of moderate and optimal abrasion resistance,at this time,the relative wear resistanceof the compos-ite material was 4.89 times that of HARDOX450 steel,4.81 times that of NM450 steel,and 5.3 times that of 30SiMn steel.As the wear process proceeds,ZTAp would gradually protrude from the iron substrate,playing an enhanced role in hindering wear;the protruding ZTAp would appear a certain slope with the iron substrate,forming a shadow protection zone,thus reducing the abrasive wear on the iron substrate.The corrosion products mainly appeared in the location of 30SiMn honeycomb columns,the honeycomb configuration ZTAp-Fe composite material area corrosion was lighter,no obvious flocculent corrosion products,the surface morphology did not ap-pear obvious damage.The introduction of ZTA ceramic particles further improved the corrosion resistance of the composite material,in the same immersion time honeycomb configuration ZTAp-Fe composite material,and 30SiMn surface appeared obvious morphological.The difference in morphology was obvious.The casting process used in this paper could effectively assemble the composite material with the mine wear-resistant steel,and greatly improve its wear resistance and corrosion resistance.
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