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

Method for displaying grain structure of invar alloy through high-temperature oxidation

A high-temperature oxidation technology for Invar alloys, which is applied in the field of high-temperature oxidation to display the grain structure of Invar alloys, can solve problems such as unsuitability, strong corrosion, and unfavorable control of corrosion time, and meet the requirements of reducing surface finish and heat preservation Effect of wide time range and simplified preparation procedure

Inactive Publication Date: 2017-02-15
TAIYUAN UNIV OF TECH
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Strong acid is highly corrosive, and the corrosion time should not be controlled. After corrosion, a layer of attachments will be formed on the surface of the sample, which is not suitable for cleaning, which will affect the effect of tissue observation.
Due to the volume limitation of the preparation solution, the chemical etching method is not suitable for etching larger samples

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 displaying grain structure of invar alloy through high-temperature oxidation
  • Method for displaying grain structure of invar alloy through high-temperature oxidation
  • Method for displaying grain structure of invar alloy through high-temperature oxidation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Cut a 20mm × 20mm × 30mm sample from the edge of the slab, grind the surface of the sample on 150#, 400#, 600#, 1000#, 1500#, 2000# water sandpaper, and rinse the surface of the sample with alcohol , hair dryer to dry. Heat the muffle furnace up to 700 °C with air in the furnace, put the prepared sample into the muffle furnace for 30 minutes, then take out the sample and let it cool naturally in the air. Peel off the iron oxide scale on the surface of the sample, and lightly grind the surface of the sample on water sandpaper, and the morphology of the Invar alloy grain structure can be seen with the naked eye.

Embodiment 2

[0034] Cut a 20mm × 20mm × 30mm sample from the edge of the slab, grind the surface of the sample on 150#, 400#, 600#, 1000#, 1500#, 2000# water sandpaper, and rinse the surface of the sample with alcohol , hair dryer to dry. Heat the muffle furnace up to 1000°C, and fill the furnace with a volume percentage of 5% O 2 +95%N 2 The mixed atmosphere of the prepared sample is put into the muffle furnace for 60 min, and then the sample is taken out at a volume percentage of 5% O 2 +95%N 2 Natural cooling in the mixed atmosphere. Peel off the iron oxide scale on the surface of the sample, and lightly grind the surface of the sample on water sandpaper, and the morphology of the Invar alloy grain structure can be seen with the naked eye.

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

A method for displaying the grain structure of invar alloy through high-temperature oxidation belongs to the field of metallographic structure analysis. The invar alloy is binary alloy and comprises 36 percent by weight of Ni and the balance of Fe; and the high-temperature oxidation conditions include oxidizing atmosphere and temperature being 600 to 1000 DEG C. A processed test sample is put into the high-temperature oxidation atmosphere to perform heat preservation for a certain time, the test sample is taken out, the oxide skin on the surface of the test sample is stripped and the test sample is lightly ground on abrasive paper, so that the clear grain structure can be observed. With the method, the defects that the corrosion time is difficult to control, the corrosive agent is toxic, dangerous and not suitable for corrosion of large test samples, and the like in the traditional chemical corrosion method are overcome. The method has the advantages that the method is simple in operation and good in display effect, time is easy to control, and the grain structure of the invar alloy can be displayed clearly.

Description

technical field [0001] The invention belongs to the field of metallographic structure analysis, and in particular relates to a method for displaying the grain structure of invar alloy by high-temperature oxidation. Background technique [0002] Fe-36Ni Invar alloy is a special alloy, also known as low expansion alloy because of its extremely small expansion coefficient. Since the Ni content is 36%, the alloy has good corrosion resistance, and it is difficult for general chemical etchant to display its grain structure quickly and clearly. [0003] The traditional method of displaying the grain structure of metal materials is chemical corrosion, and some highly corrosive acids are often used as Invar alloy corrosion agents. Patent CN105486567A discloses a chemical etching agent and its etching method for displaying the macroscopic low-magnification structure of expanded alloys. The chemical composition and proportion of the etching agent are: picric acid 3~4g, absolute alcoho...

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): G01N1/28
CPCG01N1/28
Inventor 于彦冲张少华李豪任祥王社斌
Owner TAIYUAN UNIV OF TECH