GB/T 40535.1-2021Test methods of continuous nitride ceramic fibers—Part 1: Nitrogen content (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document is the first part of GB/T 40535 "Test Method for Continuous Nitride Ceramic Fiber". GB/T 40535 has been released Lower part.

---Part 1: Nitrogen content.

Introduction

Continuous nitride ceramic fiber is one of the ideal reinforcement fibers for high-temperature wave-transmitting ceramic materials.

Arrows, spaceships, missiles, hypersonic strike weapons in nearby space, etc. With the rapid development of the domestic continuous nitride ceramic fiber industry, fiber research System units, production units, and application units all need unified test standards for assessment and evaluation, but there are currently no continuous nitride ceramics at home and abroad Fiber testing standards. Continuous nitride ceramic fiber test items mainly include tensile mechanical properties, oxygen, carbon, nitrogen, boron, sodium, iron and dielectric constant And dielectric loss test. The testing of mechanical properties, oxygen and carbon can refer to the relevant standards of continuous silicon carbide fiber testing methods. This standard system is proposed to It consists of 5 parts.

---Part 1: Nitrogen content. Specifies the test method for nitrogen in continuous nitride ceramic fibers.

---Part 2: Boron content. Specifies the test method for boron in continuous nitride ceramic fibers.

---Part 3: Impurity sodium and iron content. It specifies the test method of impurity sodium and iron in continuous nitride ceramic fiber.

---Part 4: Determination of specific surface and pore size distribution. Specified the test of specific surface and pore size distribution in continuous nitride ceramic fiber method.

---Part 5: Dielectric constant and dielectric loss. Specified the test of dielectric constant and dielectric loss in continuous nitride ceramic fiber method.

This document is the first part of the standard system, which can provide a general test method for the nitrogen content test of continuous nitride ceramic fiber Enter into technical exchanges and cooperation among various units.

1 Scope

This document specifies the sample preparation and sample preparation for the determination of nitrogen content in continuous nitride ceramic fibers by the inert gas fusion-thermal conductivity detection method. Test, test result calculation, etc.

This document is applicable to the determination of continuous silicon nitride ceramic fiber, continuous boron nitride ceramic fiber, continuous silicon nitride ceramic fiber, continuous silicon nitride ceramic fiber, continuous silicon nitride ceramic fiber, continuous silicon nitride ceramic fiber, continuous silicon nitride ceramic fiber, continuous silicon nitride ceramic fiber The total nitrogen content of continuous silicon-boron-nitrogen ceramic fiber and continuous silicon-boron-carbon-nitrogen ceramic fiber. Nitrogen content test of discontinuous nitride ceramic fiber and matrix Refer to this document. Refer to this document for the nitrogen content test of other ceramic fibers.

2 Normative references

The contents of the following documents constitute the indispensable clauses of this document through normative references in the text. Among them, dated quotations Only the version corresponding to that date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 674 Chemical reagent powdered copper oxide

GB/T 1446 General Principles of Test Methods for Performance of Fiber Reinforced Plastics

GB/T 4844 pure helium, high-purity helium and ultra-pure helium

GB/T 6003.1 Technical requirements and inspection of test sieves Part 1: Metal wire woven mesh test sieves

GB/T 8170 Numerical rounding rules and the expression and determination of limit values

GB/T 26016 high purity nickel

GB/T 26017 high purity copper

GB/T 34520.1 Continuous silicon carbide fiber test method Part 1: Bundle wire sizing rate

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Test principle

The continuous nitride ceramic fiber sample (hereinafter referred to as the sample) is put into a graphite crucible, and the sample is melted under the protection of an inert carrier gas (helium) Decomposition, the nitrogen element is released in the form of nitrogen molecules, and then carried by the carrier gas into the thermal conductivity detection cell, the thermal conductivity detection cell is based on the nitrogen and the carrier The difference in the thermal conductivity of the gas tests the nitrogen concentration and outputs the voltage signal value, and the data receiving and processing system is based on the output voltage signal value and the sample The mass calculation results in the nitrogen content of the sample, which is displayed in mass fraction.

5 Test environment

The standard test environmental conditions are implemented in accordance with the standard environmental requirements specified in GB/T 1446, temperature (23±2) °C, relative humidity (50±10)%.