Xray on-line detection and analysis method of metal material composition

Date：2022-04-24 14:53:44Views：788

By analyzing the composition of metal materials, we can understand the composition of materials, so as to monitor the product quality, analyze the products with problems, analyze the causes and eliminate hidden dangers. Metal materials are widely used in aviation, machinery, computer hardware and other fields. Generally speaking, metals are divided into pure metals, alloys, special metals and other types, but with the increasing demand for metal materials in various industries, there are more complex materials. The following is a share of metal material composition detection and analysis methods to better apply them to products.

We should know that there are about 70 kinds of metals in nature, among which iron, copper, aluminum, tin, nickel, gold, silver, lead, zinc and so on are common. The alloy refers to two or more metals or the combination of metal and non-metal, which has metal characteristics. Common alloys are steel alloys composed of iron and carbon; Stainless steel composed of iron, chromium and nickel; Brass formed of copper and zinc. So what are the methods for detecting and analyzing the composition of metal materials? The composition analysis and testing methods of metal materials are developing, and the efficiency and accuracy are also improving. The principles and characteristics of different test methods are as follows.

1. Spectrophotometry

Spectrophotometry is a method for quantitative analysis of metal elements. By measuring the absorbance and luminous intensity within the specific wavelength range of the measured substance, the substance can be analyzed qualitatively and quantitatively. It is characterized by wide application, high sensitivity, good selectivity, high accuracy and low analysis cost, but its disadvantage is that only one element can be analyzed at a time. The detection instruments include ultraviolet spectrophotometer, visible spectrophotometer and infrared spectrophotometer.

2. Titration

The main principle of titration is to use a standard concentration of test reagent to test the metal components contained in the solution. After the metal components fully react with the reagent, it can reach the final titration end point. This method is applicable to the test of various substances with a content of more than 1%. But the main disadvantage is low efficiency.

3. Atomic spectrometry

Atomic spectrometry can be divided into atomic absorption spectrometry and atomic emission spectrometry, which belongs to the traditional technology of metal material composition analysis.

The principle of atomic absorption spectrometry is to quantitatively analyze the content of the measured elements through the absorption intensity of the outer electrons of the ground atom in the gaseous state to the corresponding atomic resonance radiation of visible light and ultraviolet light. The method is suitable for gaseous atomic absorption radiation and has the advantages of high sensitivity, strong anti-interference ability, strong selectivity, wide analysis range and high precision. However, the disadvantage is that multiple elements cannot be analyzed at the same time, the sensitivity is not high for the determination of insoluble elements, and the effect is not good when measuring some complex samples.

The principle of atomic emission spectrometry is to use the characteristics of each element ion or atom to emit special electromagnetic radiation under electrical or thermal excitation. This method uses emitters for qualitative and quantitative analysis of elements. It can also test a variety of elements at the same time. The measurement purpose can be achieved by consuming less samples, and the test results can be obtained quickly. Generally, this method is used to detect the whole batch of samples, but its disadvantage is that it has low accuracy, which can only analyze the components of metal materials, and has no analysis effect on most non-metallic components.

4. X-ray fluorescence spectrometry

X-ray fluorescence spectrometry is often used to determine metal elements. It is a common method for the analysis and determination of metal materials. The test principle is that the atoms in the ground state will be in the low-energy state when they are not excited. When they are excited by the radiation lines of a certain frequency, they will become the high-energy state. In the high-energy state, they will emit fluorescence. The wavelength of this fluorescence is relatively special. Therefore, the type of elements in the sample can be determined by measuring the wavelength of these X-ray fluorescence spectral lines. Taking the spectral line intensity of the standard sample as a reference, the content of elements can be measured by comparing the spectral lines of the measured samples. This method is a qualitative and semi quantitative method, which is usually used to determine the approximate content in metal composition analysis.

5. Inductively coupled plasma spectrometry

Inductively coupled plasma atomic emission spectrometry is the most widely used method at present. The principle is to use the excitation of metal elements to produce electronic transition, which will show a certain intensity on the spectral line, and then determine the elements and content. The advantages are wide test range, high sensitivity, fast analysis speed and high accuracy. It can also test a batch of samples under one marking line and test multiple elements at the same time.

6. Spark Direct Reading Spectrometry

Spark direct reading spectrometer uses the high temperature of electric arc (or spark) to directly gasify and excite the elements in the sample from the solid state to emit the characteristic wavelength of each element. After splitting the light with a grating, it becomes a "spectrum" arranged according to the wavelength. The characteristic spectral lines of these elements pass through the exit slit and enter their respective photomultiplier tubes. The optical signal is converted into an electrical signal, which is integrated by the control and measurement system of the instrument and converted to analog / digital, Then, the percentage content of each element is tested by computer. The method has high accuracy, multi-element analysis is carried out at the same time, and the qualitative and quantitative analysis results of dozens of elements are obtained at the same time in one excitation and analysis. It is easy to operate and has fast analysis speed. It can simultaneously measure the content of dozens of elements in alloy steel or non-ferrous alloy in 20 seconds for real-time analysis. It consumes less expensive chemical reagents or special accessories. Solid samples can be tested directly. The biggest disadvantage is that there are certain requirements for the shape and size of the sample.

7. Carbon sulfur analysis

The above methods for the quantitative determination of sulfur and metal elements in steel are not accurate, but the main elements of sulfur and metal elements in steel can not be directly introduced. For this, carbon and sulfur elements can be tested by carbon sulfur analyzer. The carbon and sulfur in the sample are heated at high temperature under the condition of sufficient oxygen to oxidize into carbon dioxide and sulfur dioxide gas. After treatment, these gases enter the corresponding absorption tank to absorb the corresponding infrared radiation, which is transmitted into signals by the detector, and the results are processed and output by the computer. The method has the advantages of accuracy, speed, high sensitivity, and can be used with high and low carbon and sulfur content.

8. Oxygen and nitrogen analysis

The oxygen and nitrogen analysis method uses the oxygen and nitrogen analyzer to decompose the sample by pulse heating in inert atmosphere, and the contents of oxygen and nitrogen in various steel, non-ferrous metals and new materials are determined by infrared detector and thermal conductivity detector respectively. The advantages are high accuracy and low detection limit.

This paper can only lead you to have a preliminary understanding of the composition detection and analysis of metal materials. I hope it will be of some help to you. Shenzhen Chuangxin Online Testing Technology Co., Ltd. is a well-known professional testing organization for electronic components in China. It has three standardized laboratories with an area of more than 1000 square meters. The scope of testing services covers: testing and verification of electronic components, identification of IC authenticity, product design, material selection, failure analysis, function testing, factory incoming material inspection, X-ray testing of components, tape braiding and other testing items.