CN106969972A - A kind of material Biaxial Compression loading device for environmental scanning electronic microscope - Google Patents

Abstract

The present invention proposes a material biaxial compression loading device for environmental scanning electron microscope, including: a biaxial mechanical loading host, which is surrounded by a front side wall, a rear side wall, a left side wall, a right side wall and a base, There is a cooling platform in the middle of the base for placing the test piece; two bases are installed horizontally on the left side wall and the rear side wall respectively, and a fixed pressure head is connected to the inner end of the base; two servo motors control the loading system , the servo motor control system includes a bearing, a ball screw, a reducer and a drive unit for driving the reducer, the inner end of the ball screw is connected to the outer end of the bearing, and the outer end is connected to the output end of the reducer The inner end of the bearing is connected with the outer end of a force sensor, a grating sensor is embedded on the ball screw, and the two ball screws are correspondingly installed on the right side wall and the front side wall; when the test piece is placed on the cooling table , the fixed indenter and the movable indenter of the force sensor can correspond to the side of the test piece.

Description

A Material Biaxial Compression Loading Device for Environmental Scanning Electron Microscopy

technical field

The invention belongs to the technical field of material science, and in particular relates to a material biaxial compression loading device for an environmental scanning electron microscope.

Background technique

In materials science, the mechanical properties of materials are critical to whether materials can serve engineering. The most common material mechanical performance indicators such as Young's modulus, Poisson's ratio, compressive strength, tensile strength, and shear strength all reflect the macroscopic mechanical properties of the material. However, in practical applications, some deformation mechanical behaviors of materials cannot be well explained by the above indicators. In addition, macro-scale studies rarely involve research on damage, and micro-cracks cannot be directly observed with the naked eye, and some studies are reflected by indirect measurement methods (acoustic emission, ultrasonic, etc.), so it is necessary to seek solutions from a microscopic perspective . In recent years, the vigorous development and maturity of mesomechanics theory has provided the possibility to solve the above problems. However, the mechanical properties of materials are greatly affected by the ambient temperature and humidity, so the mechanical characterization test of materials generally requires the application of coupling fields; however, conventional coupling field test devices generally only correspond to the macro scale, and cannot observe the microscopic Structural changes. In addition, existing methods for observing the microstructure of materials, such as optical microscopes, scanning electron microscopes, and CT, generally have strict requirements on observation conditions, and it is difficult to achieve coupling field loading.

To sum up, it is very critical and necessary to consider the change of microstructure in the test of mechanical properties of materials. The scale experiment device is very lacking, and it is urgent to invent a new loading device to solve this problem.

In view of this, the present inventor has developed a material biaxial compression loading device for environmental scanning electron microscopy based on the experience in production design in this field and related fields, in order to solve the problems existing in the prior art.

Contents of the invention

The purpose of the present invention is to provide a material biaxial compression loading device for environmental scanning electron microscopy, which is used for the observation of the mesoscopic properties of materials under the action of the temperature-humidity-stress three-field coupling field, so as to overcome the defects of the prior art .

For this reason, the present invention proposes a kind of material biaxial compression loading device for environmental scanning electron microscope, it comprises:

Biaxial mechanical loading host, which is surrounded by a front side wall, a rear side wall, a left side wall, a right side wall and a base, and a cooling platform is set in the middle of the base for placement test pieces;

Two bases are installed horizontally on the left side wall and the rear side wall respectively, and a fixed pressure head is connected to the inner end of the base;

The two servo motors control the loading system, the servo motor control system includes a bearing, a ball screw, a reducer and a drive unit for driving the reducer to work, the inner end of the ball screw is connected to the The outer end of the bearing is connected, the outer end is connected with the output end of the reducer, the inner end of the bearing is connected with the outer end of a force sensor, and a grating sensor is embedded on the ball screw, wherein , the two ball screws are correspondingly installed on the right side wall and the front side wall;

Wherein, the inner end of the force sensor is connected with a moving indenter. When the test piece is placed on the cooling table, each of the fixed indenters and each of the movable indenters can correspond to the side surface of the test piece. connect.

According to the biaxial compression loading device for materials used in environmental scanning electron microscopy, a glass ceramic backing plate is respectively arranged between the fixed indenter, the movable indenter and the test piece.

The above-mentioned material biaxial compression loading device for environmental scanning electron microscope, wherein, a copper pad is arranged on the cooling platform, the bottom surface of the test piece is fixed on the copper pad, and the test piece The top surface of the piece is covered with a copper sheet with a central hole.

The above-mentioned material biaxial compression loading device for environmental scanning electron microscope, wherein, the fixed indenter and the movable indenter are respectively trapezoidal indenters, and the reducer is a worm gear reducer.

The material biaxial compression loading device for environmental scanning electron microscope as mentioned above, wherein, the drive unit includes a servo loading motor, a loading servo controller, a measurement controller and a computer, the output of the loading servo motor The end is connected to the input end of the reducer, which is electrically connected to the loading servo controller, and the measurement controller is connected to the force sensor, the grating sensor, the loading servo controller and the computer. connect.

The above-mentioned material biaxial compression loading device for environmental scanning electron microscope, wherein, the biaxial mechanical loading host is placed in the inner cavity of an environmental scanning electron microscope, the loading servo controller, the measurement controller and The computer is located outside the environmental SEM.

The material biaxial compression loading device for an environmental scanning electron microscope as described above, wherein the environmental scanning electron microscope is a FEI Quanta 650 environmental scanning electron microscope.

Compared with the prior art, the material biaxial compression loading device for environmental scanning electron microscope provided by the present invention is a mesoscale experimental device based on the mechanical properties of materials under the action of biaxial stress-temperature-humidity coupled field, through The cooling table controls the temperature of the specimen, controls the water vapor pressure around the specimen through the environmental scanning electron microscope, and realizes the control of the temperature and relative humidity (a function of temperature and water vapor pressure) of the specimen, so as to study the behavior of the material in the saturated state. mechanical properties;

The invention observes the change of the microstructure of the material in real time during the process of loading the test piece, performs digital image correlation technology analysis on the environmental scanning electron microscope pictures at different loading stages, calculates the strain field, and quantitatively analyzes the coupling of the material through the strain field measurement. The change of microstructure and the occurrence and expansion of microcracks in the process of deformation, damage and destruction under the action of field provide conditions for corresponding research.

Description of drawings

The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention. in:

FIG. 1 is a top view of a material biaxial compression loading device for an environmental scanning electron microscope of the present invention.

Fig. 2 is a side view along the direction A in Fig. 1 .

Fig. 3 is a schematic diagram of the electrical connection relationship between the measurement controller and other components in the present invention.

Explanation of main component labels:

1 Biaxial mechanical loading host 11 Front side wall

12 Rear side wall 13 Left side wall

14 Right side wall 16 Base

17 cooling table 171 copper pad

2 Base 21 Fixing head

3 Servo motor control loading system 31 Bearing

32 Ball screw 33 Reducer

34 Servo loading motor 35 Loading servo controller

36 Measurement controller 37 Computer

4 Force transducer 41 Moves the indenter

5 Grating sensor

6 Specimen 61 Glass-ceramic backing plate

62 Copper

detailed description

For this reason, the present invention proposes a material biaxial compression loading device for environmental scanning electron microscope, which includes: a biaxial mechanical loading host, which consists of a front side wall, a rear side wall, a left side wall, a right side The base is surrounded by a wall and a base, and a cooling platform is provided in the middle of the base for placing test pieces; two bases are installed horizontally on the left side wall and the rear side wall respectively, and the base A fixed pressure head is connected to the inner end of the seat; two servo motors control the loading system, and the servo motor control system includes a bearing, a ball screw, a reducer and a drive unit that drives the reducer to work. The inner end of the ball screw is connected with the outer end of the bearing, the outer end is connected with the output end of the reducer, the inner end of the bearing is connected with the outer end of a force sensor, and the ball screw A grating sensor is embedded on the bar, wherein the two ball screws are correspondingly installed on the right side wall and the front side wall; wherein, the inner end of the force sensor is connected with a moving pressure head, when the When the test piece is placed on the cooling platform, each of the fixed indenters and each of the movable indenters can be connected to the side of the test piece correspondingly.

The material biaxial compression loading device used in the environmental scanning electron microscope of the present invention is used for the observation of the mesoscopic properties of the material mechanics under the action of the temperature-humidity-stress three-field coupling field, so as to overcome the defects of the prior art.

In order to have a clearer understanding of the technical features, purpose and effects of the present invention, the specific implementation, structure and characteristics of the material biaxial compression loading device for environmental scanning electron microscopes proposed by the present invention will be described below in conjunction with the accompanying drawings and preferred embodiments And effect, detailed description is as follows. It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer" and the like indicate directions or positions The relationships are all based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention.

FIG. 1 is a top view of a material biaxial compression loading device for an environmental scanning electron microscope of the present invention. Fig. 2 is a side view along the direction A in Fig. 1 . Fig. 3 is a schematic diagram of the electrical connection relationship between the measurement controller and other components in the present invention.

As shown in Figure 1, the material biaxial compression loading device for the environmental scanning electron microscope proposed by the present invention includes:

Biaxial mechanical loading host 1, which is surrounded by a front side wall 11, a rear side wall 12, a left side wall 13, a right side wall 14 and a base 16, and a middle of the base 16 is provided with a Cooling platform 17, for placing test piece, this cooling platform 17 is used for controlling the ambient temperature around the test piece during use;

Two bases 2 are installed horizontally on the left side wall 13 and the rear side wall 12 respectively, and a fixed pressure head 21 is connected to the inner end of the base 2;

Two servo motors control the loading system 3, and the servo motor control system 3 includes a bearing 31, a ball screw 32, a speed reducer 33 and a drive unit that drives the work of the speed reducer 33, and the ball screw 32 The inner end is connected with the outer end of the bearing 31, the outer end is connected with the output end of the reducer 33, the inner end of the bearing 31 is connected with the outer end of a force sensor 4, and the ball wire A grating sensor 5 is embedded on the rod 32 to measure the displacement of the ball screw 32, wherein the two ball screws 32 are correspondingly installed on the right side wall 14 and the front side wall 11;

Wherein, the inner end of the force sensor 4 is connected with a movable indenter 41, as shown in Figure 1 and Figure 2, when the test piece 6 is placed on the cooling table 17, each of the fixed indenters 21 and each The movable indenter 41 can correspondingly contact with the side of the test piece.

Preferably, a glass ceramic backing plate 61 is arranged between the fixed indenter 21 , the movable indenter 41 and the test piece 6 respectively. Among them, by setting the glass-ceramic backing plate 61, on the one hand, the heat conduction can be slowed down; on the other hand, since the modulus of the glass-ceramic is similar to that of the rock specimen, the stiffness effect during loading can be prevented.

In addition, the cooling platform 17 is provided with a copper pad 171, the bottom surface of the test piece 6 is fixed on the copper pad 171, the top surface of the test piece 6 is covered with a copper sheet 62, the The copper sheet 61 is provided with a central hole (not shown in the figure). Wherein, the copper sheet cushion layer 171 can accelerate the heat transfer between the cooling table 17 and the test piece, and the copper sheet 62 is used to slow down the heat transfer from the test piece to the air.

As shown in the figure, the fixed pressure head 21 and the movable pressure head 41 are respectively trapezoidal pressure heads, and the reducer 33 is a worm gear reducer.

In a preferred embodiment, the drive unit includes a servo loading motor 34, a loading servo controller 35, a measurement controller 36 and a computer 37, the output end of the loading servo motor 34 is connected to the speed reducer 33 connected to the input terminal, which is electrically connected to the loading servo controller 35, and the measurement controller 36 is electrically connected to the force sensor 4, the grating sensor 5, the loading servo controller 35 and the computer 37. connections (see also Figure 3). When working, the force sensor 5 and the grating sensor 9 collect force and displacement data in real time, and transmit it to the measurement controller 36 and the computer 37, and the measurement controller 36 uses a feedback mechanism to adjust the loading servo controller 35. The rotation speed of the loading servo motor 34 is used to control the loading stability, and the computer 37 is used to collect and display measurement parameters and curves in real time, which is safe and reliable. Wherein, since the servo loading motor 34, the loading servo controller 35, the measurement controller 36, etc. are all known technologies, their specific composition and working principle will not be repeated here, and what is used in the figure is also a schematic way of painting.

As shown in Figure 2, the biaxial mechanical loading host 1 is placed in the cavity of an environmental scanning electron microscope 7, and the loading servo controller 35, the measurement controller 36 and the computer 37 are located in the environmental scanning electron microscope. SEM 7 outside. When implementing an application, preferably, the environmental scanning electron microscope 7 is an environmental scanning electron microscope modeled as FEI Quanta 650.

In actual work, the data socket (not shown) carried on the environmental scanning electron microscope 7 is electrically connected with the loading servo motor 34, the servo controller 35 and the computer 37, so as to use For data transmission, and, utilizing the water vapor generation control system (gas injection system, not shown in the figure) on the environmental scanning electron microscope 7, water vapor can be generated to control the water vapor pressure in the environmental scanning electron microscope chamber, As for the environmental scanning electron microscope, its data socket, and the water vapor generation control system, they are all prior art, and its specific composition, structure and working principle will not be repeated.

The material biaxial compression loading device for the environmental scanning electron microscope proposed by the present invention, in specific application, is to first place the test piece 6 on the cooling table 17, and pass through each of the fixed indenters 21 and the The moving indenter 41 is clamped and positioned, and then the biaxial mechanical loading host 1 is placed on the carrying platform in the environmental scanning electron microscope 7, and the water vapor generation control system and the loading servo controller 35 are connected to the cavity through the data socket. On the measurement controller 36 outside, and the objective lens 71 on the top of the environmental scanning electron microscope 7 is opposite to the central hole of the copper sheet 61, and the specific working process is as follows:

A certain loading rate is set on the two loading servo controllers 35 to control the corresponding loading servo motor 34 to drive the speed reducer 33 to drive the ball screw 32 to the bearing 31, force sensor 4 and The serial elements of the mobile indenter 41 apply loads, thereby bidirectionally loading the test piece 6, wherein each of the force sensors 4 and the grating sensor 5 collects force and displacement data in real time and transmits them to the respective measurement control On the device 23 and the computer 37, each measurement controller 36 uses a feedback mechanism to adjust the rotating speed of the corresponding loading servo motor 34, thereby controlling the stability of loading; after loading to a certain set load, while maintaining the load, use the objective lens 71 scans the image of the surface of the test piece and saves it for subsequent analysis. After that, repeat the above steps to apply loads of other values to the test piece, and record the corresponding image through the objective lens 71 until the end of the experiment.

The material biaxial compression loading device for the environmental scanning electron microscope provided by the present invention controls the temperature of the sample through the cooling platform, and controls the water vapor pressure around the sample through the environmental scanning electron microscope, thereby realizing the sample temperature and relative humidity (for temperature and the function of water vapor pressure), so as to study the mechanical properties of the material in the saturated state; the invention can realize the real-time observation of the change of the microstructure of the material during the temperature-humidity-stress coupling loading experiment in the environmental scanning electron microscope cavity. In addition, the present invention can carry out digital image correlation technology analysis on the environmental scanning electron microscope pictures at different loading stages, calculate the strain field, and quantitatively analyze the deformation, damage and microstructure of the material under the action of the coupling field through the strain field measurement. Changes and the occurrence and propagation of microcracks.

The above descriptions are only illustrative specific implementations of the present invention, and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the protection scope of the present invention.

Claims (7)

1. a kind of material Biaxial Compression loading device for environmental scanning electronic microscope, it is characterised in that described to be used for environmental scanning The material Biaxial Compression loading device of Electronic Speculum includes：

Twin shaft Mechanical loading main frame, its enclosed by a front side wall, a rear wall, a left side wall, a right side wall and a base and Into the middle of the base is provided with a cooling bench, for placing test specimen；

Two pedestals, are horizontally installed on the left side wall and the rear wall respectively, and being connected with one on the inner of the pedestal consolidates Level pressure head；

Two Serve Motor Control loading systems, the servo control system includes a bearing, a ball-screw, a reductor And the driver element of driving reductor work, the inner outer end with the bearing of the ball-screw is connected, Its outer end is connected with the output end of the reductor, and the inner of the bearing is connected with the outer end of a force snesor, described A grating sensor is embedded with ball-screw, wherein, before ball-screw correspondence is arranged in the right side wall and is described described in two Side wall；

Wherein, the inner of the force snesor is connected with a mobile pressure head, when placing the test specimen on the cooling bench, each institute Stating fixed pressure head and each mobile pressure head can correspond to and connect with the side of the test specimen.

2. it is used for the material Biaxial Compression loading device of environmental scanning electronic microscope as claimed in claim 1, it is characterised in that described A glass ceramics backing plate is respectively arranged between fixed pressure head and the mobile pressure head and the test specimen.

3. it is used for the material Biaxial Compression loading device of environmental scanning electronic microscope as claimed in claim 2, it is characterised in that described A copper sheet bed course is provided with cooling bench, the bottom surface of the test specimen is fixed on the copper sheet bed course, and the top surface of the test specimen covers A copper sheet is stamped, the copper sheet is provided with a centre bore.

4. it is used for the material Biaxial Compression loading device of environmental scanning electronic microscope as claimed in claim 3, it is characterised in that described Fixed pressure head and the mobile pressure head are respectively trapezoidal pressure head, and the reductor is a worm-gear speed reducer.

5. the material Biaxial Compression loading device for environmental scanning electronic microscope as described in any one of Claims 1-4, its feature It is, the driver element includes a servo loading motor, a loading servo controller, a Mersure Controler and a calculating Machine, the output end of the loading servomotor is connected with the input of the reductor, itself and the loading servo controller Electrical connection, the Mersure Controler and the force snesor, the grating sensor, the loading servo controller and described Calculate mechatronics.

6. it is used for the material Biaxial Compression loading device of environmental scanning electronic microscope as claimed in claim 5, it is characterised in that described Twin shaft Mechanical loading main frame is positioned in the inner chamber of an environmental scanning electronic microscope, the loading servo controller, measurement control Device and the computer bit are outside the environmental scanning electronic microscope.

7. it is used for the material Biaxial Compression loading device of environmental scanning electronic microscope as claimed in claim 6, it is characterised in that described Environmental scanning electronic microscope is the type environmental scanning electronic microscopes of model FEI Quanta 650.