ScienceDirect ® is a registered trademark of Elsevier B.V.Hardness and friction coefficient of fused silica under scratching considering elastic recovery© 2019 Elsevier Ltd and Techna Group S.r.l. %PDF-1.4 %����

HPFS® Fused Silica Standard Grade HPFS® Standard Grade, Corning code 7980, is a high purity synthetic amorphous silicon dioxide manufactured by flame hydrolysis. 0000002089 00000 n This value changes little over a wide range of frequencies. This is because these tests in reality often turn out to be just comparisons of surface quality resulting from sample preparation, small differences in which easily overwhelm any differences in intrinsic strength.The optical properties of fused silica offer striking opportunities for research and industry: the broad transparent transmission range covers the complete visible spectrum and extends far into the infrared and ultraviolet regions. 0000000016 00000 n 29 0 obj<> endobj Fused silica is a good electrical insulator, retaining high resistivity at elevated temperatures and excellent high-frequency characteristics. You have not agreed to all cookies, which limits the use of the website and performance. Unfortunately, the strength observed in practice is always far below this value. 0000051717 00000 n

It is only attacked by hydrofluoric and phosphoric acid. M͞�K���5�&�P6����Y/�nyӆ]�2þ���3�9��x7��g���c�X���[�cwk�>q����;�eS�)�1K1���E�L5�����u���I��%W=+F���:��ہ3ls�pR_oP��׆�1[6��S�9[{�]��}ZePMXE٦2���J��*�v�j�km�� j��b�[Jm�:RV �B^-E��Q����08��̨��!O��uV� ��A�8~��� ����v�QY�ܨʱK�y,A&G�`l�0��:XA��[�AXy� ��F���A��v���C}��J�y0���I � c��3Tf�c���IE�S�ُ��?�PQ���]�޹!

The purities of fused quartz and fused silica are outstandingly high. 0000001647 00000 n Optics (mostly plano-plano) out of fused silica have an excellent homogeneity and can be used for a wide range of applications - not just as a transmissive window in harsh environments, also as base material for optical filters and polarizers. The large band gap inherent in the electronic structure of the silicon-oxygen bond results in electrical conduction being limited to current carried by mobile ionic impurities. 0000056261 00000 n 0000046479 00000 n It will devitrify above about 1100°C in the presence of contaminants such as sodium, phosphorus and vanadium, with the formation of cristobalite crystals which destroy the properties of … Hardness of fused silica was determined to be varied within a relatively large range (e.g. The intrinsic IR edge arises due to lattice (multi-phonon) vibrations of the Si-O network.Controlled heat management and sustained high temperatures is crucial in many industrial processes, especially in semiconductor industries. Surface condition is very important. The theoretical tensile strength of silica glass is greater than 1 million psi. %PDF-1.5 %���� The low hydroxyl content increases infrared transparency and viscosity.

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0000053942 00000 n Abrasive blasting for surface preparation is an important step in providing a foundation for protective coatings. Because of stress concentration on surface flaws, failure most always occurs in tension rather than compression.In other words: „reliablility depends on the chance“.This could also be stated as the probability that the piece will experience a mechanical stress greater than the strength of any existing flaws. These factors have to be considered thoroughly when comparing the strengths of different “brands” of quartz glass. 0000054631 00000 n In this work, scratching on fused silica with a conical indenter and a Berkovich indenter was investigated by finite element analysis (FEA). A number of unique optical, mechanical and thermal properties have made quartz glass an indispensable material in the fabrication of high-tech products. It is always advisable to remove fingerprints, which contain traces of alkalis, from quartz glass with alcohol before heating.One of the most attractive features of quartz glass is its very low thermal coefficient of expansion (CTE).