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Preparation Of Silica Oxide Ceramic Core For Hollow-blade Casting

Posted on:2013-01-21Degree:MasterType:Thesis
Country:ChinaCandidate:M LiFull Text:PDF
GTID:2251330392968376Subject:Materials Processing Engineering
Abstract/Summary:
Ceramic core is the key for producing hollow blade. It is used to form thecomplicated structure in the blades for heat dissipation. This structure allows higheroperating temperatures, which results in higher efficiencies to be achieved in engines.Silica-based ceramic core is one of the most common used cores at present. Since it willbe shocked by the pressure of high temperature liquid during the casting process, theceramic cores need to have high quality. Based on the research before, this paper mainlyresearches in the impact of content of plastic addition; the ratio of basic material and thegrain of the power on the property of ceramic core.First,simple ceramic core of different content of plastic addition are made. Itranges from10%to20%(every1%distant). Also simple ceramic core of differentcontent of ZrO2are made. It ranges from15%to30%(every1%distant). Through thecompetition of molding rate and strength, we choose three better scheme for futureresearch.The study found that in different content of plastic addition experiment(14%/15%and18%,thirty samples for each),14%content of plastic addition has the worstflowing property. It is hard to fill the mould.15%content of plastic addition has highershrink rate and porosity due to solid diffusion compared with14%. Comparing with the15%content of plastic addition ceramic core, there is a big fall in the room temperatureflexural strength in18%content of plastic addition. It is because the bearing areadecreases as the porosity increasing. So it has the highest porosity, but roomtemperature flexural strength is too low.In different ratio of basic material research, we make silica-based ceramic cores of75%:25%;80%:20%and70%:30%. Through comparing of properties ofthe ceramic core before and after sintered as well as strengthened, it is clear that75%:25%has a better creep ability and bending strength.75%content of basicmaterial is good for the ceramic core synthetical properties.Based on the front conclusions, ceramic cores with different rate of grains areprepared. In all these prepared cores, the content of main material is75%and the plasticaddition takes up to15percent. Three different groups of grain are as bellow:7:2:1;6:3:1and5:3:2. Thirty samples for each ratio are made for the later use.Then research the properties of these samples. The results show that5:3:2has theleast liquid phase, it also has the smallest creeping rate.
Keywords/Search Tags:silica-based ceramic core, sintering, strengthen, property
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