The Study Of Preparation Technology Of Mullite Whisker Toughening 80 Alumina Oxide Ceramic

80 alumina oxide ceramic materials has a series of excellent Performance ,such as thermostable, Anti-corrosive and Wearability, so can be work at more harsh working environment than Metallic material and organic material,80 alumina oxide ceramic materials Already became or soon become the material which many domains are suitable. But it has a big Weakness that is brittleness which has serious influence it development and application space.The experiment embarks from the relations of the microstructure and the performance of 80 alumina oxide ceramic,we have study innovational a kind of Mullite whisker to Improve 80 alumina ceramic brittleness.Because of Polytropism ceramic material have no Slipping system,when it is dehiscence ,it has no Plastic deformation but direct Brittle fracture, the characteristic is Microcrack expansion.as we kown, Brittle material not have enough tensile energy,so both of Toughness and Intensity is very low. From this perspective,in order to enhance the tensile energy, we design an Ceramic whisker of excellent mechanical properties that Joins evevly in Brittle aluminum oxide ceramics substrate .so as to improve its Toughness and Intensity.because of the mullite whisker has the fine mechanical properties, Especially high temperature mechanical properties,as a intensifier joins to Aluminum oxide material substrate, mullite whisker Can greatly enhance the tensile energy of Aluminum oxide material, Thus achieves that improve remarkably aluminum oxide ceramics' brittle shortcoming.The experiment uses the industry aluminum hydroxide as the aluminum source, The admixture is the aluminum fluoride and the vanadium pentoxide,to make mullite whisker, The experiment have discussed how the different silicon source, Admixture and calcine mechanism Influenced the Coring and growth of mullite whisker, According to the analysis of whisker micro appearance,we have get Result that when takeing the Suzhou earth as the silicon source, In addition 4% vanadium pentoxides, calcining Temperature is 1400℃, mullite whisker grows best.and when 1000℃keeps warm 1h, is advantageous to the mullite coring.and more, We have studied the mechanism that how the mullite grows to Whisker, Indicated that the whisker is grows by the VS mechanism, The vanadium pentoxide vanadium is an activator,which has Reduce mullite Coring nuclear barrier,so can be Promote mullite coring. However, The aluminum fluoride function mechanism is produces the gas phase which Guide vapor diffusiou. The experiment also have explored the Relations between the ball grinding time and ratio of length to diameter of Whisker. According to the analysis of whisker microappearance, Indicated that the most appropriate dispersion system is: Take the water as the ball grinding medium, The grind ball sub-size is equal, The ball grinding process uses slow-speed of revolution 200r/min, Material: Ball: Water =1: 2:1.2, The ball grinding time is 3 hours.In the experiment,we have studyed the effect of mullite whisker Strengthen and Toughen 80 alumina oxide ceramic materials, The experiment has explored lots of Factor that influence the effect of Strengthen and Toughen,such as: the sintering temperatures, Body molding pressure, As well as sur- mullite whisker contents , According to the microstructure and mechanical properties, Indicated that when sintering temperature is 1450℃, molding pressure of 25MPa, The sur- mullite whisker is 30%,the effect of Strengthen and Toughen is the most Remarkable. The paper also have discussed the mechanism that the whisker Strengthen and Toughen high aluminum ceramic material, The Bridge jointing mechanism and Drawing out mechanism of whisker mutually synergism,The crack in the whisker place furcation expended energy is the leading role mechanism of whisker Toughening.On the base of the studying of outside joins mullite whiskers to Strengthen and Toughen 80 alumina ceramic materials,Experiment designed innovatively one kind of Redundant sintering process of mullite whisker home position to Strengthen and Toughen 80 aluminum oxide ceramic material,that is to say,we first Produces mullite whisker with Home position in the 80 aluminum oxide ceramic,then,Redundant sintering the Compound powder,So as to obtain the Compound materials which The whisker disperses evenly.in order to achieves the best effect of Strengthen and Toughen 80 alumina ceramic materials of whisker.The experiment has discussed the relations of Calcining Temperature and the mullite whisker appearance (length to diameter ratio) ,Indicated that when calcining Temperature is 1450℃, the whisker growth is most suitable. According to the microstructure and mechanical properties, Indicated that when the sinering temperature is 1500℃, the whisker effect is most obvious.