La2O3替代Al2O3和Li2O对微晶玻璃析晶及性能的影响OA

Rare-earth aluminosilicate glass-ceramics with different La2O3 contents are studied in this paper.This study is carried out to explore how La2O3 affects the properties of the materials.Al2O3 and Li2O are simultaneously substituted by La2O3 during the glass preparation.Different substitution amounts of La2O3 are set to observe the corresponding changes.The influence of this substitution on the mechanical properties of the AP(as-prepared)glass is explored.Meanwhile,the microstructure and mechanical properties of the glass-ceramics after heat treatment are also tested in detail.Various experimental methods are used to obtain accurate data.As the content of La2O3 is increased,the glass transition temperature(Tg)of the AP glass is gradually raised.The crystallization peak temperature(TP)is also increased step by step.Heat treatment is applied to the glass samples under appropriate conditions.After the heat treatment,ZrO2 crystals are precipitated in the glass matrix.Cerite-(La)crystals that contain La are also found in the heat-treated glass.These crystals are observed and confirmed by microstructural testing.When the La2O3 content is greater than 4 mol%,the crystallization tendency of the glass is reduced significantly.Glass crystallization is effectively inhibited under this condition,and no obvious crystals are formed.The mechanical properties of the crystallized glass are all improved compared with the base glass.These properties include hardness,elastic modulus,crack initiation resistance,and fracture toughness.All these properties are tested and recorded carefully.When the La2O3 content is increased to 4 mol%,the mechanical properties of both the AP glass and the crystallized glass are enhanced to the optimal level.However,when the La2O3 content exceeds 4 mol%,obvious changes occur.The mechanical properties of the AP glass begin to decline.At the same time,the crystallization amount of the glass is reduced.This reduction in crystallization amount directly leads to a decline in the mechanical properties of the crystallized glass.The excessive La2O3 is considered to damage the network structure of the AP glass,which causes the decline of its properties.