CN103058501A

CN103058501A - Hot pressing molding method of chalcogenide glass preform

Info

Publication number: CN103058501A
Application number: CN201310027853XA
Authority: CN
Inventors: 张倩
Original assignee: SUZHOU BAINASI OPTICAL TECHNOLOGY Co Ltd
Current assignee: SUZHOU BAINASI OPTICAL TECHNOLOGY Co Ltd
Priority date: 2013-01-25
Filing date: 2013-01-25
Publication date: 2013-04-24

Abstract

The invention relates to a hot pressing molding method of a chalcogenide glass perform, particularly introduces a high temperature molding method of processing a ball lens blank of the chalcogenide glass. The high temperature molding method is realized by a hot pressing molding device. The precut chalcogenide glass disc is directly pressed into a plurality of ball blanks by a hot pressing method, and then the ball blanks are finely ground and polished into the ball lenses. In such a way, the utilization rate of the chalcogenide glass material can be improved from original 17% to about 80%, so that the material utilization rate of the chalcogenide glass can be greatly improved, and the cost of infrared lens is reduced.

Description

A kind of hot-press molding method of chalcogenide glass preform

Technical field:

The present invention relates to a kind of hot-press molding method of chalcogenide glass preform, relate in particular to a kind of high-temperature molding method of processing chalcogenide glass globe lens blank, can greatly improve the material use efficiency of chalcogenide glass.

Background technology:

Chalcogenide glass (chalcogenide glass) is with sulfide, and selenide and stibnide are the glass of main component.Chalcogenide glass can be saturating for the light of mid and far infrared wave band, is a kind of important infra-red material.This year was because the price increase of rare earth element, especially germanium (Ge) was brought into use as an alternative material of the relatively low chalcogenide glass of cost so that originally much use germanium single crystal as the application of infra-red material.On the other hand, germanium single crystal can't be hot-forming as crystalline material, can only become non-spherical lens with single-point diamond machined into high costs.And chalcogenide glass can carry out hot-pressing processing as the material of vitreous state.Now general production technique is the chalcogenide glass preform precise compression molding at high temperature that adopts surface finish, thereby directly die mould goes out non-spherical lens.With respect to the turning processing of germanium single crystal, the precise forming production efficiency of chalcogenide glass is high, is fit to mass automatic production, has reduced the cost of the lens of mid and far infrared, has directly caused the rise in civilian mid and far infrared lens market, such as the passive type vehicle night vision.

The chalcogenide glass preform that is used for precise compression molding is generally globe lens, biconvex lens or plano-convex lens.Wherein the globe lens use is the most general, and general spherical diameter is that 3mm is to 15mm.The melting in the vitreosil Glass tubing of circle of the need of production of chalcogenide glass, so the glass raw material of producing all is cylindric, diameter is 50mm: at first the chalcogenide glass starting material from bulk cut out the cubes more bigger than globe lens, then cubes is ground the balling-up base, with ball base correct grinding, be polished to globe lens at last.The utilization ratio of chalcogenide glass only has about 17% to final globe lens from initial glass raw material like this, and waste is serious.The market value of considering chalcogenide glass is about between every gram 10 to 13 Renminbi, and the cost of infra-red material can account for more than 50% of final lens cost like this.

The present invention has designed a cover heat pressing forming device, and the chalcogenide glass disk that adopts a kind of hot-press method to cut in advance directly is pressed into a plurality of ball bases.And then by ball base correct grinding be polished to globe lens.The utilization ratio of chalcogenide glass material can be brought up to about 80% by original 17% like this, has greatly reduced the cost of Infrared Lens.

Description of drawings

Fig. 1 is the sectional view of heat pressing forming device;

Fig. 2 is the assembling synoptic diagram of upper/lower die and upper lower clamp;

Fig. 3 is the structure iron of mold.

Embodiment;

The below makes more detailed description to invention, and similar mark represents identical or like.Yet for better understanding, the parts shown in the accompanying drawing are to schematically show, they are drawn in proportion, namely the parts of this accompanying drawing do not represent full-size(d), these really size all be known for those of ordinary skills, therefore need not to be described in detail.

Sectional view with reference to figure 1 heat pressing forming device.Mold 1 and bed die 2 are wherein processed hemispheric die cavity array 10 to the die mould face of chalcogenide glass by the single-point diamond numerically-controlled machine all by the high temperature stainless steel manufacturing, and the roughness Ra of die cavity inwall is less than 30nm, mainly is for the ease of withdrawing pattern.Upper/lower die 1,2 diameter range are between 100 to 150mm.The diameter of chalcogenide glass disk 8 depends on the size of glass ingot, but can not surpass the diameter of upper/lower die.The thickness outline of chalcogenide glass disk 8 less than final die mould after the diameter of ball base, be generally 90% of ball base diameter.Quartz glass cover 6 is circular hollow quartz tube, the external diameter scope be 180mm between the 200mm, thickness is between 3 ~ 5mm.The quartz glass cover closed set and can be opened by the height that improves upper bed-plate on the Up/down base 7,11 of die mould machine.Resistive heater 5 evenly distributes and is wrapped in the quartz glass cover periphery, its altogether heating power at 5kw between the 8kw.

Structure iron with reference to figure 3 molds.Mold 1 non-die mould surface by the center to edge radial distribution heat radiation air drain.The structure of bed die 2 and mold 1 are in full accord.

Assembling synoptic diagram with reference to figure 2 upper/lower dies and anchor clamps.The disc surfaces of mold 1 and upper anchor clamps 3 is fitted.The axle of upper anchor clamps 3 is hollow, with space and heat radiation air drain 9 formation paths axial after mold 1 assembling.Bed die 2 is above-mentioned consistent with being assemblied in of lower clamp 4.Upper lower clamp 2,4 material and upper/lower die 1,2 material are identical, all are high temperature stainless steel, and be main in order to make thermal expansivity at high temperature consistent.

Lower mask body is introduced the die mould process.At first open the quartz glass cover 6 of sealing, place chalcogenide glass disk 8 in bed die 2 central positions.Then closed quartz glass cover 6 begins to vacuumize with upper/lower die 1,2 shaft clearance and the air drain that dispels the heat by upper lower clamp 3,4, until air pressure inside reaches 0.1MPA.At this moment resistive heater 5 is started working, the radiation of infrared penetration quartz glass cover and so that the temperature of upper/lower die reach between transition temperature Tg value 100 degree that is higher than chalcogenide glass spends to 120.Beginning die mould after upper/lower die 1,2 fully is heated evenly, mold 1 and upper anchor clamps 3 move down and chalcogenide glass disk 8 are exerted pressure during die mould, and pressure is that 20kg is between the 50kg, until upper/lower die 1,2 closures.At this moment chalcogenide glass softens fully and has very viscid flowability, and chalcogenide glass can be full of whole spherical die cavity under the effect of pressure.Close resistive heater 5 after the mould closure, and input nitrogen to the axial slits of bed die 2 and lower clamp 4, nitrogen gas stream is crossed the heat radiation air drain of bed die 2 and mold 1, extracts out by axial slits mold 1 and upper anchor clamps 3.By the gas transmission speed of control nitrogen, can control upper/lower die 1,2 rate of temperature fall, rate of temperature fall is controlled at 10 degree to 20 degree per minutes.When upper/lower die 1,2 temperature drop to when being lower than chalcogenide glass transition temperature Tg value 120 and spending, can strengthen the nitrogen displacement with fast cooling.

When upper/lower die 1,2 cool to room temperature, lifting mold 1 and upper anchor clamps 3.Because volumetric shrinkage after the chalcogenide glass cooling, its ball base can be peeled off with mold 2, and stays in the die cavity of bed die 1.Open quartz glass cover, take out each chalcogenide glass ball base with plastic tweezer.Dip at last the chalcogenide glass residue of alcohol cleaning upper and lower mould with soft cloth, in order to next hot-forming use.

Claims

1. the heat pressing forming device of a chalcogenide glass ball base,

Comprising mold and each cover of bed die, the anchor clamps that cooperate with upper/lower die, silica glass seal closure and resistive heater.

2. heat pressing forming device according to claim 1, it is characterized in that, the die mould surface of upper/lower die goes out semisphere die cavity array by the single-point diamond lathe in machining, the diameter of hemisphere with finally want the ball base of moulding consistent, its diameter range is between 3 ~ 15m.

3. according to the described heat pressing forming device of any one in the claims, it is characterized in that, the non-die mould surface of upper/lower die by the center to edge radial distribution heat radiation air drain.

4. according to the described heat pressing forming device of any one in the claims, it is characterized in that the axle of anchor clamps is hollow, with space and heat transmission gas groove claimed in claim 6 formation path axial after the upper/lower die assembling.

5. heat pressing forming device according to claim 1, wherein quartz glass cover is the hollow quartz glass pipe, closed set and can be opened by the height that improves the machine upper bed-plate on the Up/down base of die mould machine.

6. according to the described heat pressing forming device of any one in the claims, it is characterized in that hot-forming front shaft clearance and heat radiation air drain by upper lower clamp and upper/lower die vacuumizes.

7. according to the described heat pressing forming device of any one in the claims, it is characterized in that the hot-forming front infrared radiation that produces by resistive heater sees through quartz glass cover heating upper/lower die and chalcogenide glass disk.

8. according to the described heat pressing forming device of any one in the claims, it is characterized in that, beginning die mould after upper/lower die and chalcogenide glass disk fully are heated evenly, mold and upper anchor clamps move down and the chalcogenide glass disk are exerted pressure during die mould, until upper/lower die is closed.

9. according to the described heat pressing forming device of any one in the claims, it is characterized in that, close resistive heater after the mould closure, and to the axial slits of bed die and lower clamp input nitrogen, nitrogen is the heat radiation air drain of flow through molds from bottom to top, extracted out by axial slits mold and upper anchor clamps, the gas transmission speed by control nitrogen is with the rate of temperature fall of control upper/lower die.