Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for acquiring residual stress distribution from fused quartz hypothetical temperature distribution

A technology of imaginary temperature and residual stress, applied in the direction of material excitation analysis, force/torque/work measuring instrument, measuring device, etc., can solve the problems of large residual stress prediction deviation, complex and cumbersome process, and obtain the specific distribution of residual stress, etc., to achieve Easy to achieve, overcome complexity and cumbersomeness, and achieve convenient and flexible effects

Active Publication Date: 2021-09-03
LASER FUSION RES CENT CHINA ACAD OF ENG PHYSICS
View PDF28 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Existing studies have shown that to accurately predict fused silica CO 2 Laser-induced residual stress involves complex nonlinear plasticity problems. Simple models have large deviations in the prediction of residual stress. Although complex models predict residual stress more accurately, they require CO 2 The study of the whole process of laser action is extremely complicated and cumbersome, not only the specific laser parameters are required, but also the specific structural parameters dependent on the temperature of the material are required
Therefore, the existing fused silica residual stress research methods are difficult to quickly and conveniently obtain the specific distribution of residual stress

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for acquiring residual stress distribution from fused quartz hypothetical temperature distribution
  • Method for acquiring residual stress distribution from fused quartz hypothetical temperature distribution
  • Method for acquiring residual stress distribution from fused quartz hypothetical temperature distribution

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0062] Estimation of Fused Silica CO by Obtaining Residual Stress Distribution from Hypothetical Temperature Distribution of Fused Silica 2 Residual stress in laser irradiation area:

[0063] S1: Choose Corning 7980 fused silica with a size of 40mm (length)×40mm (width)×4mm (thickness). First, the fused silica is optically polished. After the polishing is completed, the fused silica is cleaned with deionized water and absolute ethanol respectively and dried, which can clean the fused silica simply and efficiently. Then, the CO is excited by RF 2 The laser passes the 1 / e through the optical system 2 A Gaussian spot with a diameter of 4.2 mm is irradiated on the fused silica. The laser power is first irradiated at 13.7 watts for 30 seconds for preheating. Then, the laser power is increased to 25.3 watts for 4 seconds, and then the laser is turned off. 2 After heating by laser irradiation, a heat-affected zone of fictitious temperature change is formed on the surface of the fu...

Embodiment 2

[0080] Adopt the method of the present invention to assess the CO reported by Matthews et al. (Proc.SPIE 2009,7504:750410) 2 The residual stress caused by the hypothetical temperature distribution in the axial depth of the laser irradiation point:

[0081] In this embodiment, steps S2, S3 and S4 are the same as in embodiment 1, the difference being steps S1 and S5:

[0082] S1: Fused silica CO obtained by confocal Raman spectroscopy reported by Matthews et al. (Proc. SPIE 2009, 7504: 750410) 2 The hypothetical temperature distribution of the axial depth of the laser irradiation point is as follows: Figure 8 Shown, respectively, 2300K peak temperature treated and quenched fused silica CO 2 Fused silica CO with peak temperature reduced from 2300K to 300K by a slope after laser irradiation point and 2300K peak temperature treatment 2 Laser irradiation point. According to CO 2 The characteristics of the spherical crown distribution of the hypothetical temperature distributio...

Embodiment 3

[0089] The method of the present invention evaluates the residual stress of silica optical fiber:

[0090] S1: A single-mode optical fiber with a diameter of 125 μm and a cladding of pure silica, annealed at 1373K for 66 hours, and then quenched in dry air to obtain an optical fiber with a uniform temperature distribution at 1373K (J.Appl.Phys.2008, 103:083506), and set doped GeO 2 The cores of have the same fictive temperature.

[0091] S2: Set the initial freezing state of the fictitious temperature of the silica fiber at 1373K as the residual stress zero point. During the subsequent temperature drop from 1373K, which is equal to the fictitious temperature, to room temperature, the silica fiber only undergoes a linear cooling and contraction process, while the fictitious temperature of 1373K The distribution no longer changes. According to the density and thermal expansion coefficient given by Huang et al. (J.Non-Cryst.Solids 1978, 127:29-37) and GeO 2 The relationship be...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for acquiring residual stress distribution from fused quartz hypothetical temperature distribution. The method comprises the following steps: S1, constructing the hypothetical temperature distribution of fused quartz; S2, drawing an initial freezing state curve and a volume change curve; S3, calculating the volume shrinkage of each position; S4, obtaining distribution of relative volume dependent variables; and S5, solving to obtain the residual stress distribution of the fused quartz. By adopting the technical scheme, the method is simple, accurate and easy to implement, the technical problem that the residual stress is complex and tedious to evaluate by the existing method is solved, and the problem that the current glass hypothetical temperature state only represents the structural state of the glass and the residual stress cannot be obtained through the distribution of the glass is solved; and the method not only can obtain the residual stress distribution of the fused quartz after CO2 laser action, but also can conveniently and flexibly obtain the residual stress of the silica fiber, and has important application value in the field of fused quartz processing.

Description

technical field [0001] The invention relates to the technical field of obtaining residual stress of optical elements, in particular to a method for obtaining residual stress distribution from the imaginary temperature distribution of fused silica. Background technique [0002] CO 2 Laser has been widely used in the processing of fused silica materials, such as: damage repair, surface polishing, cutting, surface pattern preparation, etc., and its processing usually requires depositing enough laser energy to heat the fused silica above the glass transition temperature, or even above the boiling point. Although fused silica has a relatively low coefficient of thermal expansion and is insensitive to the thermal gradient of the heating process, it can still accumulate large residual stress due to the limited relaxation time near the glass transition point when the temperature is rapidly cooled. Excessive residual stress is generally harmful. Stress and strain will not only caus...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): G01L5/00G01N21/65
CPCG01L5/0047G01N21/65
Inventor 张传超廖威陈静蒋晓龙方振华张丽娟王海军蒋晓东朱启华
Owner LASER FUSION RES CENT CHINA ACAD OF ENG PHYSICS