摘要:
A method of manufacturing a blank for a light-weight mirror. Graphite molding bodies are positioned at regular intervals on a base that functions as a mirror plate or backing plate. The base is surrounded up to the top of the molding bodies with a graphite wall. The interstices between the molding bodies and between the wall and the molding bodies are filled with granular quartz. The assembly is heated in an evacuated furnace to approximately 1730.degree. C. into a honeycomb-shaped supporting structure that is securely fastened to the base. The graphite molding bodies and wall are removed after cooling. Either a backing plate or a mirror plate in the form of another plate is applied to the resulting supporting structure.
摘要:
In the production of an article of extremely pure synthetic silicon dioxide, wherein silicon tetrachloride is mixed with water to effect hydrolysis, the resulting hydrolysis product is dried, and the resulting dried particulate product is further processed into the desired article, the improvement which comprises employing a ratio of silicon tetrachloride to water so that the hydrolysis product is in the form of a gel, distilling by-product hydrochloric acid out of the gel, preliminarily drying the gel at 100.degree. to 1000.degree. C. to produce an initial product, milling the initial product into a fine granulate at room temperature, separating from the milled granulate a fraction with a particle size of about 40 to 1000 .mu.m, and drying the screened-out granulate fraction while slowly heating to no more than 1400.degree. C. to form the resulting dried particulate product that is further processed into the desired article. As a result, high quality bubble free articles are produced.
摘要:
Disclosed is a method for the axial building up, in a vertical arrangement, of a hollow cylindrical soot body having no internal support and consisting substantially of silicon dioxide by means of at least one flame hydrolysis build-up burner serving for the soot production. In this method the soot is deposited at the beginning of the build-up onto an auxiliary body, and during the build-up the build-up burner and the growing soot body are rotated relative to one another, and the burner is at the same time held at an unvarying distance from the growing end of the hollow cylinder and centrally above the predetermined cross section of the upwardly growing end of the cylinder wall. The penetration of soot into the interior of the cylinder is prevented by means of a directed gas stream.
摘要:
A method of manufacturing practically stria-free, bubble-free, and homogeneous quartz-glass plates of any desired configuration and with a surface area that exceeds the cross-section of the full circular quartz-glass cylinder that is employed as a starting material. The cylinder is continuously lowered into a furnace shell flooded with an inert gas, in which it is heated to a flowing temperature in the range of 1700.degree. to 1900.degree. C. until some of the quartz-glass flows off into a graphite crucible. The crucible is preferably clad with zirconium-oxide.
摘要:
An epitaxy bell of transparent fused silica is provided with a flanged, thick-walled tubular piece of transparent fused silica on the side on which a process gas is exhausted. The wall thickness of the constricted portion of the bell is increased toward the transparent fused silica tubular piece.
摘要:
A generally trough-like elongated element is formed of quartz glass, open at the top, in which the side walls (2) which, preferably, have inclined portions (4) merging with the bottom wall (1) of the trough, are formed with through-slits (3), and the bottom wall is formed with slots (5) cut therein, leaving, however, the end portions solid and uncut; the end portions are formed with positioning or alignment notches (6) extending in a direction transverse to the bottom wall which, preferably, is formed with a recess or notch for engagement with a transport apparatus. The side walls preferably have holes extending, in longitudinal alignment, through the solid end portions to permit passage of the tines of a handling fork (8) therethrough. The slits (3) and the slots (5) provide for three-point suspension of disk or plate-like semiconductor substrates for handling and introduction, for example, into a treatment or diffusion furnace or tube.
摘要:
A quartz glass envelope tube for the preparation of a light guide fiber blank, the tube being in the form of a laminate in which the inner layer consists essentially of quartz glass made from rock crystal and the outer layer of synthetic quartz glass. Good mechanical properties, especially tensile strength, are thereby achieved.
摘要:
Articles, such as fragile, delicate semiconductor wafers, in a first carrier member are caused to pass nearly, but not quite wholly, into a second carrier member by being pushed--against gravity--thereinto. The carrier members are then subjected to a displacement, e.g. by inversion, and said articles are allowed to drop wholly into said second carrier member. The further distance travelled by the articles after rotational displacement of a housing retaining the carrier members is very small, e.g. about 2 mm.
摘要:
To make quartz glass crucibles suitable for drawing of single crystal silicon for electronic semiconductor applications, granular crystalline quartz or amorphous quartz glass is introduced into a rotating hollow mold which has gas-pervious wall regions at the side walls and bottom thereof, for example by having bores extending through a metal mold or being made of porous, sintered material. After introducing the raw material, a heat source, such as an electric arc, is introduced into the hollow mold, causing first sintering and then melting of an inner layer; upon introduction of the hollow mold, a vacuum is applied to the outside of the hollow mold, for example between the housing and the mold body, and, during continued rotation, to draw out any included gases and cause melting-together of vacuoles which, otherwise, might form due to included spaces and gases within the granular filling material. The vacuum is maintained during melting and rotation, heating being interrupted when a sufficienty thick inner wall of molten material has been formed, with an adjacent layer of sintered material leaving, however, granular material immediately adjacent the inner walls of the hollow mold to provide for heat insulation of the molten layer with respect to the hollow mold and protect the surface of the mold. The finished crucible can be ejected by introducing compressed air, rather than vacuum, to the outside of the hollow mold. Suitable vacuum is a pressure of less than 5,000 Pa, preferably less than 1,000 Pa.
摘要:
A process for electrodeposition of palladium is described wherein an electroplating bath comprising a palladium(II) compound is employed which electroplating bath is ammonia-free. The bath contains water and an amine of the formula ##STR1## wherein x=0 or 1 and when x=0: ##STR2## and when x-1: R.sup.1 =N(CH.sub.3) (CH.sub.2).sub. 3 NH.sub.2, NH(CH.sub.2).sub. 2 NH.sub.2, NH(CH.sub.2).sub. 2 NH(CH.sub.2).sub. 3 NH.sub.2, NH.sub.2, OH or C.sub.1-4 -alkoxy, R.sup.2, R.sup.3, R.sup.4 =H or CH.sub.3.The amine permits the electrodeposition of palladium at a current density above 2.5 A/dm.sup.2 and the resultant coatings are semi-glossy to glossy and are characterized by firm adhesion and freedom of pores. The coatings have only low internal tensions.