阅读说明：本技术 一种用于电镜观察的微米级球形颗粒截面的制备方法 (Preparation method of micron-sized spherical particle section for electron microscope observation ) 是由 邓超 文婷婷 洪睿 杨帅 周仕远 刘施峰 于 2021-01-08 设计创作，主要内容包括：本发明公开了一种用于电镜观察的微米级球形颗粒截面的制备方法,包括如下步骤：(1)将导电胶带粘贴于导电金属基体上；(2)取微米级球形颗粒粉末平铺粘在导电胶带上,并吹走多余粉末；(3)将粘有粉末的导电金属基体置于离子束抛光机内进行抛光,采用平面抛光模式,抛光角度为0～2°,抛光电压和时间为5～8kV 5～40min+3～5kV 5～20min+0.5～2kV 5～20min,即可获得满足扫描电镜观察的颗粒截面。本发明不需要包埋处理,不用消耗额外的制样耗材；时间短,成本低,操作性强；耗时仅为截面抛光模式的十分之一,抛光效率高；获得的样品有效面积大,用于扫描电镜观察的可选择区域多。(The invention discloses a preparation method of a micron-sized spherical particle section for electron microscope observation, which comprises the following steps: (1) adhering the conductive adhesive tape to the conductive metal substrate; (2) taking micron-sized spherical particle powder, flatly paving and adhering the micron-sized spherical particle powder on a conductive adhesive tape, and blowing away redundant powder; (3) and (3) placing the conductive metal matrix adhered with the powder in an ion beam polishing machine for polishing, wherein a plane polishing mode is adopted, the polishing angle is 0-2 degrees, the polishing voltage and time are 5-8 kV 5-40 min + 3-5 kV 5-20 min + 0.5-2 kV 5-20 min, and the particle section meeting the observation of a scanning electron microscope can be obtained. The invention does not need embedding treatment and consumes no extra sample preparation consumables; the time is short, the cost is low, and the operability is strong; the time consumption is only one tenth of that of a cross section polishing mode, and the polishing efficiency is high; the obtained sample has large effective area and more selectable regions for observation of a scanning electron microscope.)

1. A preparation method of a micron-sized spherical particle section for electron microscope observation is characterized by comprising the following steps:

(1) adhering the conductive adhesive tape to the conductive metal substrate;

(2) taking micron-sized spherical particle powder, flatly paving and adhering the micron-sized spherical particle powder on a conductive adhesive tape, and blowing away redundant powder;

(3) and (3) placing the conductive metal matrix adhered with the powder in an ion beam polishing machine for polishing, wherein a plane polishing mode is adopted, the polishing angle is 0-2 degrees, the polishing voltage and time are 5-8 kV 5-40 min + 3-5 kV 5-20 min + 0.5-2 kV 5-20 min, and the particle section meeting the observation of a scanning electron microscope can be obtained.

2. The method of claim 1, wherein: the conductive adhesive tape is a double-sided conductive carbon adhesive tape or a copper adhesive tape.

3. The method of claim 1, wherein: the conductive metal matrix is copper or aluminum.

4. The method of claim 1, wherein: the polishing voltage and time are 5-8 kV 5-15 min + 3-5 kV 5-20 min + 0.5-2 kV 5-20 min.

5. The method of claim 4, wherein: the polishing voltage and time are 7kV 5min +4kV10min +1kV10 min.

6. The method of claim 1, wherein: the size of the conductive metal matrix is 8mm multiplied by 8 mm.

7. The method of claim 1, wherein: the diameter of the micron-sized spherical particle powder is 5-20 μm.

8. The method of claim 1 or 7, wherein: the micron-sized spherical particles are metal, inorganic nonmetal or ceramic spherical particles.

9. The method of claim 8, wherein: the micron-sized spherical particles are LiNiCoMnO₂A battery anode material or a pure titanium microsphere material.

10. The method of claim 1, wherein: the ion beam polishing machine is an argon ion polishing machine.

Technical Field

The invention belongs to the technical field of sample preparation of scanning electron microscopes, and particularly relates to a preparation method of a micron-sized spherical particle section for electron microscope observation.

Background

Cross-sectional samples of micron-sized spherical particles have been lacking in high quality means of preparation. Conventional methods include embedded damascene polishing, which is a complicated and time-consuming process, and the polishing solution may contaminate, corrode, or damage the surface of the sample. The improved means include focused ion beam cutting, ultra-thin slicing, and ion beam polishing, wherein the focused ion beam cutting has precise positioning, high cutting efficiency for single particles, and good observation surface, but the high-energy ion cutting inevitably introduces ion implantation pollution. In addition, the focused ion beam cutting equipment has high cost, which causes difficulty in popularization of the method. The ultrathin section method can obtain a smooth spherical particle section, and is suitable for high-quality scanning electron microscope observation, however, before the spherical particle is cut, resin embedding and curing pretreatment needs to be adopted, the time consumption is long, the efficiency is low, and only a plurality of particle sections can be obtained in each sample preparation. Neibo Ying et al adopt an ion beam polishing technology to prepare a particle section sample, the section obtained by the method has good flatness and a large area, and can meet the observation requirement of a scanning electron microscope (Neibo Ying et al, preparation of NCM particle section sample [ J ], an analytical instrument, 2019, 3: 90-93); the method comprises the steps of mixing spherical particles with carbon conductive glue solution, embedding the mixture with aluminum foil, tabletting, cutting to form a section polishing sample, and then transferring the section polishing sample to an ion polishing machine for section polishing, wherein the polishing voltage is 6.5kV, and the time is 6 h.

The existing ion beam polishing technology for preparing a cross-section sample has the following defects that firstly, the sample pretreatment step is complicated, and the carbon conductive glue solution is used as a dispersing agent, a fixing agent and a filling agent, so that the raw material consumption is large and the cost is high; and secondly, the ion polishing adopts a cross section polishing mode, so that the polishing time is long and the efficiency is low.

Disclosure of Invention

The invention aims to solve the problems and provides a preparation method of a micron-sized spherical particle section for electron microscope observation.

In order to achieve the purpose, the invention adopts the technical scheme that:

a preparation method of a micron-sized spherical particle section for electron microscope observation is characterized by comprising the following steps:

(1) adhering the conductive adhesive tape to the conductive metal substrate;

(2) taking micron-sized spherical particle powder, flatly paving and adhering the micron-sized spherical particle powder on a conductive adhesive tape, and blowing away redundant powder;

(3) and (3) placing the conductive metal matrix adhered with the powder in an ion beam polishing machine for polishing, wherein a plane polishing mode is adopted, the polishing angle is 0-2 degrees, the polishing voltage and time are 5-8 kV 5-40 min + 3-5 kV 5-20 min + 0.5-2 kV 5-20 min, and the particle section meeting the observation of a scanning electron microscope can be obtained.

Preferably, the conductive tape is a double-sided conductive carbon tape or a copper tape.

Preferably, the conductive metal matrix is copper or aluminum.

Preferably, the polishing voltage and time are 5-8 kV for 5-15 min + 3-5 kV for 5-20 min + 0.5-2 kV for 5-20 min.

Further preferably, the polishing voltage and time are 7kV 5min +4kV10min +1kV10 min.

Preferably, the conductive metal matrix is 8mm x 8mm in size.

Preferably, the micron-sized spherical particle powder has a diameter of 5 to 20 μm.

Preferably, the micron-sized spherical particles are metallic, inorganic non-metallic or ceramic spherical particles.

Further preferably, the micron-sized spherical particles are LiNiCoMnO₂A battery anode material or a pure titanium microsphere material.

Preferably, the ion beam polisher is an argon ion polisher.

The invention has the beneficial effects that: the spherical particle powder is directly paved on the metal matrix for polishing pretreatment, embedding treatment is not needed, and extra sample preparation consumables are not consumed. The pretreatment steps are few, the time is short, the cost is low, and the operability is strong; secondly, the ion polishing adopts a plane polishing mode, the polishing time is short, the time consumption is only one tenth of that of a cross section polishing mode, and the polishing efficiency is high; and thirdly, the effective area of the sample obtained in the plane polishing mode is large, and the selectable area for observing by the scanning electron microscope is large.

Drawings

FIG. 1 is a LiNiCoMnO₂Scanning electron microscope images of the surfaces of the spherical particles before ion polishing of the battery anode material powder.

FIG. 2 is a scanning electron micrograph of a cross section of a spherical particle after ion polishing in example 1.

FIG. 3 is a scanning electron micrograph of a cross section of a spherical particle after ion polishing in example 2.

FIG. 4 is a scanning electron micrograph of a cross section of a spherical particle after ion polishing in example 3.

FIG. 5 is a scanning electron microscope image of the surface of the spherical particles before ion polishing of the industrial pure titanium microsphere powder.

FIG. 6 is a scanning electron micrograph of a cross section of a spherical particle after ion polishing in example 4.

FIG. 7 is a scanning electron micrograph of a cross section of a spherical particle after ion polishing in example 5.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to be limiting.

The experimental procedures in the following examples are conventional unless otherwise specified.

The embodiment of the invention uses main reagents and devices:

LiNiCoMnO₂battery positive electrode material: the diameter of the powder of a certain lithium ion battery anode material manufacturer in China is 5-20 mu m, and the scanning electron microscope image of the surface of spherical particles before ion polishing is shown in figure 1.

Industrial pure titanium microsphere material: the diameter of the powder of a certain domestic metal powder manufacturer is 2-15 μm, and the scanning electron microscope image of the surface of the spherical particles before ion polishing is shown in FIG. 5.

Argon ion polishing machine: brand name: gatan, type: ilions 697.

Example 1

Preparing a micron-sized spherical particle section for observation by a scanning electron microscope, and operating according to the following steps:

(1) adhering a double-sided conductive carbon adhesive tape to an aluminum metal substrate with the size of 8mm multiplied by 8 mm;

(2) using toothpick to pick up small quantity of LiNiCoMnO₂The powder of the battery anode material is flatly paved and adhered on the conductive adhesive tape, and the excessive powder is blown away by a blower, and only the powder adhered on the conductive adhesive tape is remained;

(3) and (3) polishing the aluminum metal matrix with the powder in an argon ion polishing machine in a plane polishing mode, wherein the angle of an ion gun is 2 degrees, and the polishing voltage and time are 7kV 5min +4kV10min +1kV10min, so that a section meeting the observation requirement of a scanning electron microscope can be obtained, and the scanning electron microscope image of the section of the spherical particles after ion polishing is shown in figure 2.

Example 2

Preparing a micron-sized spherical particle section for observation by a scanning electron microscope, and operating according to the following steps:

(1) adhering the double-sided conductive copper adhesive tape to a copper metal substrate with the size of 8mm multiplied by 8 mm;

(2) using toothpick to pick up small quantity of LiNiCoMnO₂The powder of the battery anode material is flatly paved and adhered on the conductive adhesive tape, and the excessive powder is blown away by a blower;

(3) the copper metal matrix with the powder is placed in an argon ion polishing machine for polishing, a plane polishing mode is adopted, the angle of an ion gun is 0.5 degrees, the polishing voltage and time are 7kV 5min +4kV10min +1kV10min, the section meeting the observation requirement of a scanning electron microscope can be obtained, and the scanning electron microscope image of the section of the spherical particles after ion polishing is shown in figure 3.

Example 3

Preparing a micron-sized spherical particle section for observation by a scanning electron microscope, and operating according to the following steps:

(1) adhering the double-sided conductive copper adhesive tape on an aluminum metal substrate with the size of 8mm multiplied by 8 mm;

(2) using toothpick to pick up small quantity of LiNiCoMnO₂The powder of the battery anode material is flatly paved and adhered on the conductive adhesive tape, and the excessive powder is blown away by a blower;

(3) the copper metal matrix with the powder is placed in an argon ion polishing machine for polishing, a plane polishing mode is adopted, the angle of an ion gun is 0 degree, the polishing voltage and time are 7kV 5min +4kV10min +1kV10min, and then the section which meets the observation requirement of a scanning electron microscope can be obtained, and the scanning electron microscope image of the section of the spherical particles after ion polishing is shown in figure 4.

Example 4

Preparing an industrial pure titanium micron-sized spherical particle section for scanning electron microscope observation, and operating according to the following steps:

(1) adhering a double-sided conductive carbon adhesive tape to an aluminum metal substrate with the size of 8mm multiplied by 8 mm;

(2) a small amount of industrial pure titanium microsphere material powder is stuck by a toothpick, laid flat and stuck on the conductive adhesive tape, and the excess powder is blown away by a blower, so that only the powder stuck on the conductive adhesive tape is remained;

(3) the aluminum metal matrix with the powder is placed in an argon ion polishing machine for polishing, a plane polishing mode is adopted, the angle of an ion gun is 0 degree, the polishing voltage and time are 8kV 15min +4kV10min +1kV10min, the cross section meeting the observation requirement of a scanning electron microscope can be obtained, and the scanning electron microscope image of the cross section of the spherical particles after ion polishing is shown in figure 6.

Example 5

Preparing an industrial pure titanium micron-sized spherical particle section for scanning electron microscope observation, and operating according to the following steps:

(1) adhering the double-sided conductive copper adhesive tape to a copper metal substrate with the size of 8mm multiplied by 8 mm;

(2) a small amount of industrial pure titanium microsphere material powder is stuck by a toothpick, laid flat and stuck on the conductive adhesive tape, and the excess powder is blown away by a blower, so that only the powder stuck on the conductive adhesive tape is remained;

(3) the copper metal matrix with the powder is placed in an argon ion polishing machine for polishing, a plane polishing mode is adopted, the angle of an ion gun is 0 degree, the polishing voltage and time are 8kV 40min +4kV 20min +1kV 20min, and then the section which meets the observation requirement of a scanning electron microscope can be obtained, and the scanning electron microscope image of the section of the spherical particles after ion polishing is shown in figure 7.

As can be seen from the scanning electron micrographs of FIGS. 1-7, the spherical particles of examples 1-5, prepared by the process of the present invention, had intact particles, no fragmentation or contamination, clear spherical edges, and intact internal structures. The effective area of the obtained cross section sample is large, a cross section with the area of tens of square centimeters can be obtained after ion beam polishing in theory, and the number of selectable regions for scanning electron microscope observation is large. After ion beam polishing by the method, the section of the spherical particle can be shown under low observation times. And polishing parameters are optimized, and an observation section with good flatness can be obtained. Under high observation times, the size and distribution information of the internal pores of the spherical particles can be obtained.