Analysis On Microstructure And Performance Of Surface Of Lining Ceramic Layer

According to the problems of technology research in surface engineering which the complicated preparation technology and the lining ceramic layer can be flaked easily, this paper adopts a new lining ceramic technology--pre-permeating lining ceramic, lining ceramic layer which is uniform, dense, and a gradient distribution of particles was obtained. The technique would take green body pore-making in advance, and then make nanometer ceramic composite powder entering into the hole of green body, and sintering in the condition of atmosphere protection, the interface of metallurgical bonding between ceramic composite powder and material of green body were formed. Because strengthening phase (nanometer ceramic powder) has been entered into the pore of green body before sintering, so this method was called of pre-permeating lining ceramic. The method overcomes the disadvantage of which it can be flaked easily between green body and ceramic layer in the past.This experiment detected the microstructure of lining ceramic layer through composition design and sample preparation, chemical composition and parameters of pre-permeating lining ceramic were determined correctly, lining ceramic layer and its interface were characterized correctly. Sawdust and starch so as to be pore inducing materials during the experiment, they were well mixed with green body of iron, Nickel etc. powder before dry pressing, preparation of green body with holes by pre-exclusion of plasticizer; Slurry is made of main raw material which is the powder of 5Y-ZrO2 nanometer and Nickel, then daubing them on the interface of green body with holes; The samples were obtained in vacuum or argon protection environment after sintering.Starch which is the best pore former was determined by experiment, the hole formed was well distributed which the addition amount of starch is 10%, it can meet technical requirement of pre-permeating lining ceramic; It is found that ZrO2 ceramic phase had a descending trend from interface to green body by means of energy dispersive analysis; The interface of sintering samples between composite powder and matrix metal were divided into two types by photos of SEM analyzing, One is the morphology of inter-phase region between grey and white formed by composite powder after sintering, the vague interface with mutual infiltration of composition was formed between this region and matrix metal around. Another is composite powder was formed isolated particles for separation of metal around after sintering. Experiment shows that lining ceramic layer density has a lower which it is sintering in lower temperature, and loose in microstructure; Lining ceramic layer of compact and combines strongly can be obtained which it is sintering in higher temperature, therefore, it can be obtained that the best range of lining ceramic temperature is 1020～1050℃. The depth of lining ceramic layer had no significant change which ceramic composite powder for the contents of ZrO2 increased from 10% to 40%, but the distribution density of ceramic particles in lining ceramic layer increased gradually.