Zro₂-al₂o₃ Ceramics Enforcement High Chromium Cast Iron Matrix Composites

By means of microstructure observation,X-ray Difractometer(XRD),Scanning Electron Microscopy(SEM) with Energy Dispersive Spectrometer(EDS),rockwell hardness test,impact-toughness test,abrasive wear test and observation of the wear surface and the as-cast morphology of impact fracture,the microstructure,mechanical properties and wear resistance of parent material were researched.The reasonable content of parent material were made.The effects of different nickelizing factors on MMCs were investigated using Energy Dispersive Spectrometer(EDS) and pattern observation.ZrO₂-Al₂O₃ ceramics enforcement high chromium cast iron matrix composites were made.Experimental results show that:the as-cast microstructure of high chromium cast iron without Ti consists of austenite,martensite and carbides.M₇C₃,M₂₃C₆ are the main carbide types of chromium.The distribution of Ti is almost uniform in carbide and matrix.The microstructure of high chromium cast iron consists of martensite, retained austenite and carbides after heat treatment.There is no change in carbide types of chromium after heat treatment.The effect of Ti on the parent material was investigated.At cast condition,The hardness of the parent material without Ti are 55.75HRC and impact toughness are 9.43J/cm².while the hardness of the parent material with Ti are 58.75HRC and impact toughness are 11.18J/cm².The reasonable heat treatment technics of high chromium cast iron is destabilized at 1050℃and tempered at 450℃.In this heat treatment condition,the hardness and impact toughness of the parent material without Ti are 62.5HRC and 9.1J/cm²,while the hardness of the parent material with Ti are 64HRC and impact toughness are 9.3 J/cm².Comparing the effect of the activation technology on the cladding of ceramics, The reasonable activation technology is:PdCl₂,0.25g/L;HCl,10mL/L.The reasonable nickelizing technology is:The reasonable time of nickelizing is 30min,The reasonable temperature is 35～40℃,The reasonable PH is 4.5-5.5. The interface of ZrO₂-Al₂O₃ ceramics enforcement high chromium cast iron matrix composites is better.The reasonable point of pouring is 1400-1450℃.With the increasing of ceramics gas rate the impact toughness is increasing,while the impact toughness is reducing first and increasing late.The reasonable ceramics gas rate is 80%.The experimental result shows that:The reasonable technology is nickelizing and parent material with Ti.The reasonable heat treatment technics of ZrO₂-Al₂O₃ ceramics enforcement high chromium cast iron matrix composites is destabilized at 1050℃and tempered at 450℃.In this heat treatment condition,the impact toughness of ZrO₂-Al₂O₃ ceramics enforcement high chromium cast iron matrix composites is 9.1J/cm²,while the impact toughness is 1.1ing.