Additive Manufacturing Of Silica Glass And Its Applications

Glass is a widely used material which plays important roles in industry,scientific research and our daily life.Due to the hard and brittle properties and the high liquidus temperature of glass,traditional processing technologies are restricted when applying to glass.This also restricts the development of the glass industry.However,the superior optical transparency,incomparable thermal and chemical stabilities make the research on novel glass manufacturing technologies continue.Additive manufacturing(AM),also designated as 3D printing,is a newly developed technology in recent three decades.As this technology may bring great impact on traditional manufacturing,it has acquired great interest in both industry and academy.Compared with metals,polymers and ceramics,the AM technologies for glasses have fallen behind.Thus,the development of glass AM technologies is urgent to glass industry.Among all the categories of the AM technologies,vat photopolymerization is the most attractive one to us for the best manufacturing resolution and superior efficiency.The success of vat photopolymerization on the ceramics AM also brought us the confidence of applying this technology on glasses,which have similar properties as the ceramics.In this thesis,we realize silica glass AM with vat photopolymerization and change the optical properties of these silica glasses with doping for various applications.The detailed contents include:(1)The vat photopolymerization technology for silica glass AM.In this section,we introduce a UV curable suspension loaded with 37 vol%amorphous SiO2 nanoparticles for silica glass AM with vat photopolymerization,and test this suspension by transforming it to transparent silica glass with UV curing and heat treatments.We realize silica glass vat polymerization AM from this suspension with liquid crystal display(LCD)and stereolithography(SL)approaches.Furthermore,we discuss the influence of light sources to the photopolymerization and the heat treatment steps of the silica glass AM by comparing these two approaches,and shorten the heat treatment period to 15 h.(2)AM of the doped silica glass with solution impregnation.In this section,we dope the silica glass obtained from vat photopolymerization with rare earth and transition elements by solution impregnation.The rare earth elements include Ce,Tb and Eu,and the transition elements include Co,Ni,Cu and Au.We measure the optical properties,including absorption,photoluminescence and light scattering,of the doped silica glasses.By using the energy transfer mechanism in co_doped silica glass,we realize the modulation of the emission spectra of the rare earth doped silica glass.Furthermore,we develop a selective doping method to realize the manufacturing of one piece of glass with varied optical properties in each part,which has potential in the manufacturing of integral glass devices.(3)AM of the phosphor in silica glass devices with vat photopolymerization and its applications in white light illuminations.In this section,we prepare the YAG:Ce phosphor in silica glass with the photopolymerization process.The YAG:Ce phosphor in silica glass maintains the photoluminescence properties of the YAG:Ce phosphor and the quantum efficiency reaches 78.9%.Compare with other phosphors in glass devices,ours have much better thermal stability,and this YAG:Ce phosphor in silica glass can be transformed to light conversion devices with vat photopolymerization directly.We demonstrate the applications of the YAG:Ce phosphor in silica glass in high power white LED and laser illuminations,and characterize the properties,including intensity and efficiency,of the illumination devices.