| The technology of material knowledge is one of the keyroles, which have been prompting the development of the economyof society. It is one of the important pillars of the structof society's economy, and the Bioceramics Materials is theimportant part of the new kinds of materials. As the InorganicBiomedical Materials, the Bioceramics Material has been paidmore attention and applied extensively just nearly twentyyears. The Bioceramics Materials are mainly applied for thesubstitution or the rebuild of the hard tissue of Human bodywhich was damaged. Contrasted with metals and organicmaterials, the merits of the bioceramics materials are withoutpoisonous by effects, better biological compatibility withbiological tissue and anti-decayed performance. Because of themany merits mentioned above, the bioceramics materials havebeen used clinically frequently. About forty kinds ofbioceramics materials have been made about 50 kinds ofsubstitutions on aspects of Medicine and Orthopedics and havecome into the market.According to the activity, the Bioceramics Materials canbe divided into three types: the first is Inert Bioceramics,the second is Active Bioceramics and the third is AbsorbtableBioceramics. Now days, in the bioceramic materials which hasbeen used in clinic frequently, hydroxyapatite (HAP) is the mostpopular. The molecular formula of hydroxyapatite isCa10(PO4)6(OH)2, and also called HAP or HA, a kind of quaternioninorganic apatite and its crystal lattice parameter isa=b=0.9421nm , c=0.6882nm, and the ratio of Ca/P is1.67theoretically. HA are the most valuable active bioceramicsmaterials for use, it is the main inorganic component ofbackbone animals' bones and teeth (70%-90% in human bones),and its structure is also like those animals' bones and teeth.HA has good biological compatibility, nobiological noxious so that it can be used extensively as thesubstitution or the rebuild of the hard tissue of Human body,such as teeth plant, substitution of backbone, and it is betterthan metals and polymer. Therefore, HA is a kind of promisingactive bioceramics materials. However, although owning so manyadvantages, HA is not perfect. HA is unfit for supporting heavyburden because of its low mechanical performance. Recently,some people try to improve Hap's property by mixing somematerial else.High-pressure method is the important method in materialsynthesize, as a kind of typical extreme condition, the rolesof High-Pressure Method are shortening the distances betweenthe atoms effectively, changing the states of electronsand affecting phrases change. In the condition of high pressureand high temperature, the materials are given high energy. Sothe High Pressure Method is effective to synthesize newmaterials. However, now the High Pressure Method is reportedrarely for study Bioceramics that have been studied in many ways.High-Pressure Method has been developed fast recent years.In this paper, we select hydroxyapatite (HA) and Al2O3 as thestarting materials, and mix them in low energy MBM by ten hoursto produce composite materials. Finally, burning the compositesunder the normal pressure or high pressure for studying it'sstructure and mechanics properties.We test TG-DTA, XRD, and Raman, and so on to find the affectsof the conditions to crystal structure and microstructure forapplications, offering experimental facts for creating betternew bioceramics materials. The HAP original powder is preparedin the chemical precipitation method in this paper. We use 500tons Belt press, which is responsible for heating up and fixthe conditions on low pressure 2.0GPa, 450oC, 1000oC;highpressure 3.90GPa, 450oC, 1000oC, and keeping the pressure andtemperature 40 minutes every time to test the thermal stabilityand mechanics properties.Results and Discussion1 . The results of DTA/TG show that the endothermic peak ofAl2O ranging from 230oC to 270oC, which lose little mass usuallyreflects the escape of some impurity and moisture. While theHAP's center of exothermic peaks is 322 oC and 370 oC which losemuch mass indicates the original HAP powder can be changed instructure or crystallizes further. And the composite also havethe same phenomenon.2. XRD's show that the composite haven't changed thestructure of crystal through raising the temperature under thenormal pressure, and the effect of MBM is reduce the crystalparticles in size and cut down the degree of crystalling, theeffect of burning under high temperature help HAP crystalline.3. HAP-Al2O3 composite's crystal particles raise in size verynotable when we improve the temperature from 440 oC to 1000 oC,and the change in size isn't notable excepting this.4. The result of the Raman shows that the Raman peaks dropwhen we raise the content of Al2O3 which keep up with the changeof XRD, Raman peaks disappears and then appear again when thetemperature raising. Which keep up with the change of TG-DTA.5. The intensity resist pressure raise when we raise thecontent of Al2O3, at the same time the crystal particles becomesmaller, we also find the intensity resist pressure changenotable when temperature change.6. Burning the composite under high pressure is good atimproving the crystalling of the composition , we didn't findnew peaks and which show that HAP and Al2O3 haven't respond undersolid state.The degree of crystalline is worse when the content of Al2O3 ishigh and the same time the change of crystal particle changein size, we have found a phenomenon that the color of HAP-Al2O3composite have change under high pressure or high tempreture.The composite's color is white before and after high pressurewhen without burning, but the color change from white to browncolor when high pressure and high temperature. We can't explainthe phenomenon now.7. The results of HV show that the values of HAP and HAP-Al2O3(5%) composite under 3.9Gpa than 2.0Gpa when without burring,and the value of HAP increase notablely, but the change is smallwhen mix Al2O3.In conclusions, high temperature improves crystalling ofHAP and HAP-Al2O3 composites. High pressure led to reduce ofcrystal in size. The intensity of resist pressure rise whenmixing Al2O3 in HAP. The HV of HAP is more improved with moreAl2O3.
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