CAJ | 학술논문

采用高温熔融法制备了不同成核剂Fe_2O_3及ZrO_2含量的SiO_2-Al_2O_3-MgO-F系玻璃试样,用差示扫描量热仪、X射线衍射仪以及扫描电子显微镜研究了成核剂对此微晶玻璃析晶特征的影响.结果表明:在所研究的微晶玻璃中,随着ZrO_2含量增加,玻璃转变温度和析晶温度略有提高.当玻璃中ZrO_2含量超过5.0%(质量分数,下同)时,玻璃转变温度有较大提高,而析晶温度却大大降低.同时添加ZrO_2和Fe_2O_3提高了玻璃转变温度,并且在850～900 ℃及925～960 ℃出现了2个析晶放热区间.对应第1个析晶温度区间,堇青石晶体在玻璃基体中均匀析出,析出晶体为枝状,最终形成多边星形.第2个放热区间温度对应云母晶体的析出,析出晶体呈片层状,在星形晶体间析出.随着玻璃中Fe_2O_3含量的增加,玻璃转变温度和放热峰温度都逐渐提高,而且2个放热峰温度的间隔程度增加.同时也发现ZrO_2和Fe_2O_3的加入都抑制了云母晶体的析出.
채용고온용융법제비료불동성핵제Fe_2O_3급ZrO_2함량적SiO_2-Al_2O_3-MgO-F계파리시양,용차시소묘량열의、X사선연사의이급소묘전자현미경연구료성핵제대차미정파리석정특정적영향.결과표명:재소연구적미정파리중,수착ZrO_2함량증가,파리전변온도화석정온도략유제고.당파리중ZrO_2함량초과5.0%(질량분수,하동)시,파리전변온도유교대제고,이석정온도각대대강저.동시첨가ZrO_2화Fe_2O_3제고료파리전변온도,병차재850～900 ℃급925～960 ℃출현료2개석정방열구간.대응제1개석정온도구간,근청석정체재파리기체중균균석출,석출정체위지상,최종형성다변성형.제2개방열구간온도대응운모정체적석출,석출정체정편층상,재성형정체간석출.수착파리중Fe_2O_3함량적증가,파리전변온도화방열봉온도도축점제고,이차2개방열봉온도적간격정도증가.동시야발현ZrO_2화Fe_2O_3적가입도억제료운모정체적석출.
The glass samples with various contents of Fe_2O_3 and ZrO_2 as nucleating agents were prepared by melt-quenching methods in the SiO_2-Al_2O_3-MgO-F system and the crystallizing behaviors were investigated using differential scanning calorimeter, X-ray diffraction and scanning electron microscopy techniques. The results indicate that both the transition temperature (Tg) and the crystallizing temperature have a bit rise with the increase of ZrO_2 contents in the glass system studied. In the sample with more than 5.0wt% ZrO_2 additive, an obvious increases of Tg, but a great decreases of crystallizing temperature are observed. The additions of a pair of Fe_2O_3 and ZrO_2 increase the Tg and induce two exothermal peaks occurred at 850～900℃ and 925～960℃. The dendritic phases of cordierite, which are crystallized at the first exothermal peaks temperature, are homogeneously precipitated in the residual glass and formed the star-shape crystals eventually. The second exothermal peaks are corresponded to the crystallization of mica phases, which are precipitated of interdendritic cordierite phases and formed the plate shapes. With the increases of Fe_2O_3 contents, the Tg and crystallization temperature are both increased and the gap between the two exothermal peaks is broadened. Also, it is found that the incorporation of Fe_2O_3 or ZrO_2 suppresses the crystallization of mica crystal.