【作者】 张浩；

【导师】 郑伟宏； 孙波；

【作者基本信息】 武汉理工大学 ， 材料工程（专业学位）， 2024， 硕士

【摘要】 目前透明锂铝硅体系微晶玻璃因其优异的力学性能和化学强化性能等特点已成功应用于电子领域,但存在化学稳定性差、玻璃熔制成型困难等缺点。而透明钇铝硅微晶玻璃具备较高的透过率和优异的力学性能,在电子领域具有巨大的应用潜力。本文通过熔融法和二步热处理制度制备出透明的钇铝硅微晶玻璃,并研究Y₂O₃、Li₂O/Na₂O及P₂O₅引入量对钇铝硅玻璃析晶和其微晶玻璃性能的影响。研究结果表明:（1）随着Y₂O₃引入量增加,玻璃转变温度和析晶峰温度呈逐渐增大趋势,玻璃的弹性模量、硬度、热膨胀系数和密度均逐渐增加。Y³⁺通常具有较高的配位数,对氧离子争夺能力较强,在一定程度上对硅酸盐玻璃网络结构起积聚作用,从而导致钇铝硅玻璃黏度较大,条纹比较明显,并且更难析晶。此外,在900℃/2h的热处理制度下,可以析出以钇稳定氧化锆晶体为主晶相的透明微晶玻璃。（2）在固定钇铝硅玻璃组成中其它组分的含量和保持引入碱金属氧化物Li₂O与Na₂O总含量为6 wt%的情况下,分别用0 wt%、2 wt%、4 wt%以及6 wt%的Li₂O等量取代Na₂O,发现玻璃转变温度、软化温度和析晶峰温度逐渐降低,Li₂O在YAS玻璃中的助熔效果明显好于Na₂O。Li₂O作为网络外体使钇铝硅玻璃结构逐步解聚,玻璃的析晶能力逐渐增强。在680℃/10 h+750℃/1 h热处理制度下,可以制备出晶体大小一致且分布均匀并以钇稳定氧化锆为主晶相的透明微晶玻璃,其中2%Na₂O+4%Li₂O微晶玻璃具有良好的综合性能:维氏硬度为646 Hv,断裂韧性为1.07 MPa·m^1/2,透过率为85.7%。（3）在保持钇铝硅玻璃中其它组分含量不变的条件下,加入0.5～5 wt%的P₂O₅,随着P₂O₅含量增加,玻璃转变温度和析晶峰温度逐渐增加。P₂O₅作为一种网络形成体,提高了钇铝硅玻璃的网络聚合度,抑制了玻璃的析晶。随着析晶温度升高,依次析出钇稳定氧化锆和Li（Al Si₂O₆）等晶体。在700℃/10 h+750℃/1h热处理制度下,随着P₂O₅含量增加,钇铝硅玻璃的成核位点减少,结晶度下降,从而导致玻璃维氏硬度显著下降,而透过率变化不大。此时,含有0.5 wt%P₂O₅纳米微晶玻璃的综合性能最好:维氏硬度为674 Hv,断裂韧性为1.09MPa·m^1/2,透过率为87.6%。更多还原

【Abstract】 Recently transparent lithium aluminosilicate glass-ceramics has been successfully used in electronic field due to its excellent mechanical and chemical strengthening properties,but there are shortcomings such as poor chemical stability and difficulties in glass melting and moulding.Transparent yttrium aluminosilicate glass-ceramics has high transmittance,excellent mechanical properties and has great potential for application in the field of electronics.In this thesis,transparent yttrium aluminosilicate glass-ceramics was prepared by melting method and two-step heat treatment system,and the effects of the content of Y₂O₃,Li₂O/Na₂O and P₂O₅ on the crystallization and properties of yttrium aluminosilicate glass-ceramics were investigated.The studies are as follows:（1）With the increase of Y₂O₃ introduction,the glass transition temperature and crystallization peak temperature showed a gradual increase trend,and the elastic modulus,hardness,thermal expansion coefficient,as well as density of the glass increased gradually.Y³⁺usually has a high coordination number,and has strong ability to compete for the oxygen ions,which to some extent plays a role in the accumulation of the network structure of the silicate glass,resulting in the yttrium aluminosilicate glass with higher viscosity,more obvious streaks,and more difficult to precipitate.In addition,transparent glass-ceramics with yttrium stabilized zirconia as the main crystalline phase can be precipitated under the heat treatment procedure of 900℃/2h.（2）With the content of other components in the composition of yttrium aluminosilicate glass fixed and the total content of introduced alkali metal oxides Li₂O and Na₂O maintained at 6 wt%,Na₂O was replaced by 0 wt%,2 wt%,4 wt%,and 6wt%of Li₂O in equal quantities,respectively.It was found that the glass transition temperature,the softening temperature,and the crystallization peak temperature were gradually decreased,and the fluxing effect of Li₂O was significantly better than that of Na₂O in the YAS glass.Li₂O acts as a network modifier to depolymerize the structure of yttrium aluminosilicate glass,and the crystal precipitation ability of the glass is gradually enhanced.Under the heat treatment system of 680℃/10 h+750℃/1 h,transparent glass-ceramics with uniform crystal size and distribution and yttrium stabilized zirconia as the main crystalline phase can be prepared,of which 2 wt%Na₂O+4 wt%Li₂O glass-ceramic has favorable overall performance:the Vickers hardness is 646 Hv,the fracture toughness is 1.07 MPa·m^1/2,and the transmittance is85.7%.（3）Under the condition of keeping the content of other components in yttrium aluminosilicate glass unchanged,0.5～5 wt%of P₂O₅ was added,and with the content of P₂O₅ increased,the glass transition temperature and the peak temperature of the precipitation crystals were gradually increased.P₂O₅,as a kind of network formers,increased the network polymerisation of yttrium aluminosilicate glass,and inhibited the precipitation crystals of the glass.With the crystallization temperature increased,crystals such as yttrium stabilized zirconia and Li（Al Si₂O₆）were precipitated sequentially.Under the heat treatment procedure of 700℃/10 h+750℃/1 h,the nucleation sites of yttrium aluminosilicate glass decreased with the increase of P₂O₅content,and the crystallinity decreased,which led to a significant decrease in the Vickers hardness of the glass,while the transmittance did not change much.At this time,the nano-microcrystalline glass containing 0.5 wt%P₂O₅ had the better overall performance:the Vickers hardness is 674 Hv,the fracture toughness is 1.09 MPa·m^1/2,and the transmittance is 87.6%.更多还原