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1.
采用传统熔融冷却法获得了以P2O5为成核剂的Li2O-Al2O3-SiO2系统基础玻璃,通过差热分析确定了使该玻璃微晶化的热处理条件,并获得了不同热处理温度下Li2O-Al2O3-SiO2系统低膨胀微晶玻璃;利用X射线衍射分析和扫描电子显微镜对晶化试样的物相和微观结构进行了研究,讨论了热处理制度对玻璃的析晶及热膨胀系数的影响,研究结果表明:以P2O5为成核剂,采用不同热处理制度能获得Li2-Al2O3-SiO2系统低膨胀微晶玻璃;在析晶初始温度下进行热处理,析出β-石英晶体,但晶体生长缓慢,结晶程度低;提高晶化温度,析出β-锂辉石晶体且晶体生长迅速。  相似文献   

2.
Li2O-Al2O3-SiO2系统微晶玻璃是一种具有耐高温、耐热冲击、热膨胀系数低等性能的新型玻璃材料,受到科研人员的广泛关注.通过改变Li2O-Al2O3-SiO2系统微晶玻璃的基础配方以及热处理制度,制备了具有较低热膨胀系数的Li2O-Al2O3-SiO2系统微晶玻璃.结合运用差热热重、X射线衍射、扫描电镜等测试分析方法,研究性能与其组分、微观结构和热处理制度之间的相互联系.结果表明:通过对热处理制度的调整,促进了玻璃的析晶过程,核化温度和晶化温度有所降低.玻璃析出的主晶相为LiXAlXSi1-XO2,最低热膨胀系数达到25.365×10-7℃-1.  相似文献   

3.
以CaO-A l2O3-SiO2为主要原料,采用烧结法制备出微晶玻璃.利用DSC确定了核化温度和晶化温度.利用XRD和SEM研究微晶玻璃的物相组成和显微结构.通过研究热处理温度对微晶玻璃性能的影响,可得出在780℃核化1h、948℃晶化2h时,微晶玻璃的性能最好.  相似文献   

4.
研究了热历史对一种CaO(MgO)-Al2O3-SiO2系统微晶玻璃的晶化性能和压痕硬度的影响。利用X射线衍射分析了微晶玻璃的晶相种类;结合光学显微镜观察,探讨了热处理温度对晶相体积百分数的影响;确定了硬度与测试荷载之间的关系。实验结果表明,随着热处理的提高,微晶玻璃的晶相含量增加,微晶玻璃的硬度增大  相似文献   

5.
热处理制度对微晶玻璃结构和性能的影响   总被引:4,自引:1,他引:4  
将DTA-TG、XRD、SEM等测试方法和微晶玻璃性能测试相结合,研究晶化温度的改变对MgO-AlO2-SiO2系微晶玻璃微观结构和性能的影响。确定合理的热处理制度,制备具有良好的力学性能和微观结构的微晶玻璃。  相似文献   

6.
在MgO-Al_2O_3-SiO_2系统玻璃中分别引入TiO_2、ZrO_2作为晶核剂,采用"两步法"热处理制备微晶玻璃,并研究晶核剂对其析晶行为的影响。实验结果表明,以TiO_2为晶核剂时,MAS玻璃析晶峰温度较低,析晶速率较慢,易于可控析晶,当热处理制度为770℃/4h+950℃/2h,微晶玻璃中析出MgTi_2O_5与MgAl_2O_4两种晶相,且微晶玻璃外观透明。以ZrO_2作为晶核剂时,MAS玻璃析晶峰温度升高,析晶速率增加,在830℃/4h+1 000℃/2h热处理后,析出镁铝硅酸盐及ZrO_2晶体,其中镁铝硅酸盐与β-石英结构类似。  相似文献   

7.
热历史对CaO(MgO)—Al2O3—SiO2系统晶化性能的硬度的影响   总被引:2,自引:0,他引:2  
研究了热历史对一种CaO(MgO)-Al2O3-SiO2系统微晶玻璃的晶化性能和压痕硬度的影响,利用X射线的射分析了微量玻璃的晶相种类,结合光学显微镜观察,探讨了热处理温度对晶相体积百分数的影响,确定了硬度与测试荷载之间的关系,实验结果表明,随着热处理的提高,微晶玻璃的晶相含量增加,微晶玻璃的硬度增大。  相似文献   

8.
目的 利用高炉矿渣、粉煤灰和废玻璃为原材料制备矿渣微晶泡沫玻璃,在确定微晶泡沫玻璃配方范围的基础上,对制备微晶泡沫玻璃的核化和晶化工艺参数进行了优化,使之具有轻质高强的优良性能.方法 采用粉末烧成法工艺和正交试验优化设计的试验手段.结果 严格控制核化及晶化工艺参数对制备具有较高抗压强度的矿渣微晶泡沫玻璃是十分必要的。晶化温度对微晶泡沫玻璃抗压强度影响显著,晶化温度不宜过高,否则材料的抗压强度明显下降、结论 确定了热处理的优化条件:核化温度为740℃,核化时间为50min,晶化温度为910℃,晶化时间为40min、在优化条件下制备的矿渣微晶泡沫玻璃由泡径2~3mm的气孔、晶体和玻璃相组成,XRD显示主晶相为透辉石;表观密度946kg/m^3,抗压强度17.9MPa,吸水率为0.25%,可代替实心粘土砖作为墙体材料使用.  相似文献   

9.
以Li2O-Al2O3-SiO2-K2O-Na2O为玻璃系统,研究了热处理对制备主晶相为偏硅酸锂(Li2O·SiO2)的微晶玻璃空穴基片载体材料的影响和试验优化,通过正交实验设计分析了热处理制度对玻璃基片中曝光区域的结晶程度和结晶点阵的扩散程度的影响规律,优化后的处理参数为曝光时间120min,核化温度580 ℃,核化时间90min,晶化温度610 ℃,晶化时间50min.  相似文献   

10.
半透明四硅氟云母微晶玻璃的合成   总被引:1,自引:0,他引:1  
本文研究了SiO_2-MgO-MgF_2-K_2O系统四硅氟云母微晶玻璃的制备工艺,通过热膨胀曲线、差热分析及扫描电镜观察,探索了微晶玻璃的热处理制度,用x-ray衍射方法确定了晶类及结晶率,并对材料的半透明性能作了理论探讨。  相似文献   

11.
B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with different Al_2O_3 contents(1mol%, 3mol%, 5mol%, and 7mol%) was prepared, and it was intended to be used as lead-free and low-melting glass sealants for solid oxide fuel cells. The effects of Al_2O_3 content on the structures, thermal properties, and sintering behaviors of the B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass were investigated in detail. The Al_2O_3 content largely influenced the structures and thermal properties of the glass. When the Al_2O_3 content 5mol%, the transition temperature of the glass decreased with the Al_2O_3 content, while the crystallization temperature increased with the Al_2O_3 content. However, higher Al_2O_3 content degraded the stability of the glass. The B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with 5 mol% Al_2O_3 content exhibits the optimal sintering densification characteristics and can be used as glass sealants for solid oxide fuel cells.  相似文献   

12.
在聚甲醛(POM)/聚氧化乙烯(PEO)共混改性材料的成型加工过程中,采用了3种不同的热处理方法来改变共混材料的结晶形为,并且分析了对力学性能的影响.结果表明:共混材料在POM结晶温度下保温2h,然后在PEO结晶温度下保温2 h,共混材料中POM的结晶度最大,PEO没有结晶,POM和PEO之间的分子作用力增强,有利于吸收能量增加韧性,因此可以获得综合力学性能良好的POM/PEO共混材料.  相似文献   

13.
实验以Li2O-Al2O3-SiO2(LAS)系统微晶玻璃为研究对象,根据LAS系统玻璃三元相图设计玻璃组成,并在基础组分不变的前提下,选择了La2O3等5种稀土氧化物采取外加法进行掺杂,应用高温粘度仪测试分析了玻璃液的高温粘度。通过调整稀土氧化物的种类和用量,制备出了熔制温度相对较低、具有较好的透明性、较高的强度和热膨胀系数接近于零的微晶玻璃。结果表明:La2O3、Y2O3、CeO2、Er2O3及Gd2O3都具有降低玻璃液粘度的作用,其中以La2O3的作用最大。  相似文献   

14.
SiO2-Al2O3-ZrO2 glasses with different nucleating agents were crystallized under special processing schedule. The microstructure and mechanical properties of the glass-ceramics in SiO2-Al2O3-ZrO2 system were investigated by differential scanning calorimetry, scanning electron microscopy, X-ray diffraction and three-point bending method. The results show that ZrO2 is not an effective nucleating agent in SiO2-Al2O3-ZrO2 system, while TiO2 is effective for the separation of spinel, and P2O5 facilitates solubility of ZrO2 in glass and crystallization. The main crystalline phases of the glass-ceramics are spinel, anorthite and tetragonal zirconia. With the increase of ZrO2 content in the glass, glass-ceramics show higher bending strength (120 MPa) than others.  相似文献   

15.
共聚醚酯的合成工艺及其性能   总被引:2,自引:0,他引:2  
合成了一系列含有磺酸盐基团和不同聚乙二醇添加量的共聚醚酯(COPEET),研究了COPEET合成的特殊规律以及COPEET的常规性能、热性能及吸湿性能的变化.结果表明:添加PEG体系的COPEET缩聚反应时间均较常规PET缩聚反应时间缩短;COPEET的羧基含量极低;二甘醇含量随PEG添加量的增加而下降;PEG添加量的增加会降低COPEET的玻璃化转变温度;PEG添加量小于40%时,有利于COPEET的结晶,而过高的添加量会妨碍COPEET的结晶;COP—EET的熔融温度随着PEG添加量的增加而下降;COPEET的饱和含水率随PEG添加量的增加而有规律地增加.  相似文献   

16.
Novel biodegradable aliphatic polyesters,poly(butylene succinate-co-triethylene glycol succinate)(P(BS-co-TEGS))and poly(butylene succinate)(PBS),were synthesized through a two-step procedure of esterification and polycondensation with succinic acid and1,4-butanediol/triethylene glycol as raw materials as well as tetrabutyl titanate and diphenylphosphinic acid as the co-catalysts.The chemical structure and molecular weight of the copolymers were characterized by 1~H nuclear magnetic resonance(~1H NMR)and gel permeation chromatography(GPC),respectively.In addition,thermal properties,crystal structure and mechanical properties were also analyzed with various techniques.P(BS-co-TEGS)exhibited more excellent mechanical properties than PBS,especially in elongation at break.Meanwhile,the crystal structure and thermal stability of the P(BS-co-TEGS)have hardly changed.The crystallinity of P(BS-co-TEGS)was lower than that of PBS and decreased with the increase of mole ratio of triethylene glycol.With the increase of TEGS unit molar composition,the melting point(T_m),crystallization temperatures(T_c)and heat of fusion(ΔH_m)of P(BS-co-TEGS)decreased,while glass transition temperature(T_g)increased.  相似文献   

17.
Novel biodegradable aliphatic polyesters, poly(butylene succinate-co-triethylene glycol succinate) (P(BS-co-TEGS)) and poly(butylene succinate) (PBS), were synthesized through a two-step procedure of esterification and polycondensation with succinic acid and 1, 4-butanediol/triethylene glycol as raw materials as well as tetrabutyl titanate and diphenylphosphinic acid as the co-catalysts. The chemical structure and molecular weight of the copolymers were characterized by 1H nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC), respectively. In addition, thermal properties, crystal structure and mechanical properties were also analyzed with various techniques. P(BS-co-TEGS) exhibited more excellent mechanical properties than PBS, especially in elongation at break. Meanwhile, the crystal structure and thermal stability of the P(BS-co-TEGS) have hardly changed. The crystallinity of P (BS-co-TEGS) was lower than that of PBS and decreased with the increase of mole ratio of triethylene glycol. With the increase of TEGS unit molar composition, the melting point (Tm), crystallization temperatures (Tc) and heat of fusion (Δ Hm) of P(BS-co-TEGS) decreased, while glass transition temperature (Tg) increased.  相似文献   

18.
在PMMA聚合过程中加入经过修饰的纳米TiO2,测定了添加纳米TiO2的PMMA的性能.结果表明:纳米TiO2在PMMA中分散比较均匀,添加纳米TiO2能够有效地提高PMMA的紫外屏蔽、玻璃化温度和热变形温度,改善材料的光学、力学和热学性能.  相似文献   

19.
SnO-ZnO-P2O5三元系统封接玻璃的研究   总被引:4,自引:0,他引:4  
给出了SnO-ZnO—P2O5三元系统(简称SZP系统)玻璃的大致形成区,研究了该系统玻璃的转变温度及软化温度范围内粘度与商用基体材料的膨胀相容性、抗水性能等,并加入合适的填料以调节SZP系统的膨胀性能。该组成设计的SZP玻璃料的抗水性可与含铅封接玻璃相比拟。  相似文献   

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