Seawater environment biaxial mechanical loading device based on synchrotron radiation X-ray diffraction
By using a biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction, the problem of in-situ characterization of microcrack corrosion process of marine materials in the prior art has been solved, and high-resolution corrosion product analysis has been achieved, providing technical support for the study of failure mechanism of marine materials.
Patent Information
- Application Number
- CN202511721390.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-10
AI Technical Summary
Existing technologies struggle to achieve in-situ characterization of microcrack corrosion processes in materials under complex stress conditions and seawater corrosion environments. Insufficient time, space, and penetration capabilities lead to reduced prediction accuracy.
A biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction was adopted. By using high-intensity synchrotron X-rays and high-resolution detectors, combined with a three-dimensional adjustment platform and a well-sealed seawater environment chamber, the device can accurately scan and locate the tip of microcracks and capture the dynamic corrosion process.
It achieves high temporal resolution, spatial resolution, and penetration capability in the microcrack corrosion process, provides accurate corrosion product analysis, and supports the study of multi-field coupled failure mechanisms of marine materials.
Smart Images
Figure CN121499563A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of material testing in seawater environments, and in particular to a biaxial mechanical loading device for seawater environments based on synchrotron X-ray diffraction. Background Technology
[0002] The stress corrosion problem faced by marine materials under near-service conditions is far more harmful than the effect of a single factor. In the actual marine environment, the materials are not simply subjected to static loads, but are in a complex stress state composed of fluctuating stress, high pressure, ocean current impact, etc. At the same time, their surfaces are continuously subjected to the synergistic erosion of high concentrations of chloride ions, dissolved oxygen and microorganisms in seawater. This extreme mechanical-chemical coupling effect will induce the initiation of microcracks on the material surface. At present, conventional research on the stress corrosion mechanism mainly focuses on in-situ characterization. By performing in-situ characterization such as X-ray diffraction (XRD) and Raman spectroscopy on samples after stress corrosion, and then deriving the chemical reaction process through inversion, the corrosion process cannot be clearly explained, resulting in reduced prediction accuracy. Therefore, it is necessary to develop equipment and testing methods that can realize in-situ characterization of stress corrosion process. At present, in-situ research based on laboratory-grade X-ray diffraction, Raman spectroscopy and other equipment has the following shortcomings: (1) Insufficient time resolution, making it difficult to capture dynamic evolution process: The formation of chemical products at the tip of microcracks is a dynamic and rapid evolution process. (1) Laboratory XRD equipment requires several minutes or even tens of minutes to acquire a single diffraction pattern, which cannot capture the continuous transformation of transient intermediate phases and the real-time response to environmental changes; (2) The characterization sensitivity and accuracy are insufficient, making it difficult to identify key trace products: The content and crystallinity of corrosion products generated in the early stage of microcracks are low and surrounded by matrix materials. Laboratory XRD equipment is not capable of identifying products with low content and weak diffraction signals, and it is easy to miss key intermediate phases; (3) The spatial resolution is insufficient, making it difficult to locate micro-area analysis: The size of microcracks is at the micrometer level. The laboratory measurement signal is a mixed signal of crack tip, matrix material and surface corrosion products. It is impossible to focus the analysis accuracy on the extremely narrow area of the crack tip where the reaction occurs, resulting in inaccurate chemical information; (4) The penetration ability is insufficient, making it difficult to cope with the simulation of real service environment: The characterization equipment must penetrate seawater and experimental cabin windows. The weak penetration ability of laboratory XRD leads to a sharp drop in signal-to-noise ratio, which limits the possibility of conducting experiments under conditions close to real working conditions. Summary of the Invention
[0003] The purpose of this invention is to provide a biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction, which enables in-situ characterization and analysis of corrosion product evolution at cracks under near-service conditions of complex stress and seawater corrosion environment, and provides technical support for revealing the microcrack corrosion failure mechanism of marine materials under near-service conditions.
[0004] To achieve the above objectives, the present invention provides a biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction, comprising a ray generator, and a slit, a mechanical loading device, and a detector arranged sequentially along the optical path of the ray generator; a seawater environment tank is arranged in the center of the mechanical loading device, and a three-dimensional adjustment platform is arranged below the mechanical loading device.
[0005] Preferably, the X-ray generator is a synchrotron X-ray emission source, which is a high-intensity, high-collimation synchrotron radiation source, and the X-ray energy range is 30-80keV; the beam size is adjusted to the micrometer level through the slit to meet the experimental requirements of different fields of view; the detector has high spatial resolution and high frame rate acquisition capability, and can capture transient diffraction signals generated by the dynamic process of the test.
[0006] Preferably, the three-dimensional platform uses a screw or servo motor to achieve adjustment of the XYZ three-axis degrees of freedom for the mechanical loading device.
[0007] Preferably, the structure of the seawater environment tank in the mechanical loading device is as follows: the seawater environment tank adopts an octagonal structure, the top of the seawater environment tank is provided with a water inlet, and the bottom is provided with a drain outlet, so that seawater can be injected and discharged through the water inlet and the drain outlet. A loading hole is provided at 90-degree intervals on the outside of the seawater environment tank, and a follow-up sealing structure is provided on the outside of the four loading holes. The front and back of the seawater environment tank are provided with high light transmittance transparent windows, and the high light transmittance transparent windows are fixed to the seawater environment tank by flanges.
[0008] Preferably, the seawater environment tank is made of corrosion-resistant titanium alloy material, the water inlet and the drain hole are sealed by flanges, the high-transmittance transparent window is made of sapphire glass, and the follow-up sealing device is made of multi-layer rubber composite material.
[0009] Preferably, the mechanical loading device has the following structure: it includes two fixed surfaces, and four servo loading mechanisms are arranged between the two fixed surfaces. The adjacent servo loading mechanisms are spaced 90 degrees apart. Each servo loading mechanism has a loading rod and a sample clamp arranged at its end. The loading rod and the sample clamp extend into the seawater environment tank through the loading hole. The sample clamp is responsible for fixing the test sample. The servo loading mechanism performs stress control, displacement control and strain control on the sample through the loading rod.
[0010] Therefore, the present invention employs the above-mentioned biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction, which has the following advantages: In this invention, the synchrotron radiation X-ray source has the following superior characteristics compared with laboratory light sources: (1) High throughput: High-quality diffraction or spectral data can be obtained in milliseconds; (2) High collimation: High-precision trace element analysis can be achieved; (3) Excellent spatial resolution: Synchrotron radiation X-ray beams can be focused to the submicron scale to achieve precise scanning and positioning of microcrack tips; (4) High penetration capability: Synchrotron radiation X-rays can penetrate media such as seawater environment and environmental chamber windows, and can be coupled with an in-situ test system that is closer to the actual service conditions (submerged in seawater solution with stress), so as to realize in-situ observation of material corrosion and crack propagation processes in real seawater corrosion environment and biaxial complex stress state; Utilizing the high brightness and high resolution characteristics of synchrotron radiation X-rays, accurate acquisition and analysis of weak corrosion product signals can be achieved; The system has a reasonable structure, good sealing, and high transmittance, and is suitable for long-cycle stress corrosion experiments; It can provide a reliable experimental platform and data support for the study of multi-field coupling failure mechanisms of marine engineering materials.
[0011] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0012] Figure 1 This is an overall diagram of the biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction of the present invention; Figure 2 This is a front view of the mechanical loading device in the biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction of the present invention. Figure 3 This is a schematic diagram of the seawater environment tank in the biaxial mechanical loading device for seawater environment based on synchrotron radiation X-ray diffraction of the present invention. Reference numerals: 1. Mechanical loading device; 2. Three-dimensional adjustment platform; 3. X-ray generator; 4. Detector; 5. Fixed surface; 6. Seawater environment chamber; 7. Servo loading mechanism; 8. Loading rod; 9. Sample clamp; 10. Loading hole; 11. Follow-up sealing structure; 12. High-transmittance transparent window; 13. Flange; 14. Water inlet; 15. Drain outlet; 16. Slit. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Specific model specifications need to be selected and determined according to the actual specifications of the device, etc. The specific selection calculation method adopts existing technology in the art, and therefore will not be described in detail.
[0014] Example like Figures 1-3 As shown, this invention provides a biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction, including a ray generator 3. A slit 16, a mechanical loading device 1, and a detector 4 are arranged sequentially along the optical path of the ray generator 3. The ray generator 3 specifically adopts a synchrotron X-ray emission source, which is a high-intensity, high-collimation synchrotron radiation source, and the generated X-ray energy range is 30-80keV. The beam size is adjusted to the micrometer level through the slit 16 to meet the experimental requirements of different fields of view. The detector 4 has high spatial resolution and high frame rate acquisition capability, and can capture the transient diffraction signal of the dynamic process of the test.
[0015] A three-dimensional adjustment platform 2 is installed below the mechanical loading device 1, and a seawater environment tank 6 is installed in the center of the mechanical loading device 1. The three-dimensional adjustment platform 2 adopts existing common solutions such as screws or servo motors to achieve the XYZ three-degree-of-freedom adjustment of the mechanical loading device 1, thereby adjusting the spatial position of the mechanical loading device 1. The specific structure of the seawater environment tank 6 in the mechanical loading device 1 is as follows: The seawater environment tank 6 adopts an octagonal structure. The top of the seawater environment tank 6 is provided with a water inlet 14 and the bottom is provided with a drain outlet 15. Seawater is injected and discharged through the water inlet 14 and the drain outlet 15. A loading hole 10 is provided at 90-degree intervals on the outside of the seawater environment tank 6. Each of the four loading holes 10 is provided with a follow-up sealing structure 11. The front and back of the seawater environment tank 6 are provided with high-transmittance transparent windows 12, which are fixed to the seawater environment tank 6 by flanges 13.
[0016] The seawater environment tank 6 is made of corrosion-resistant titanium alloy. The water inlet 14 and the drain hole are sealed by flanges. The high-transmittance transparent window 12 is made of sapphire glass. The follow-up sealing structure 11 is made of multi-layer rubber composite material.
[0017] The mechanical loading device 1 has the following structure: two fixed surfaces 5, and four servo loading mechanisms 7 are set between the two fixed surfaces 5. Each servo loading mechanism 7 has a loading rod 8 and a sample clamp 9 set at its end. The loading rod 8 and the sample clamp 9 extend into the seawater environment tank 6 through the loading hole 10. The sample clamp 9 is responsible for fixing the test sample. The servo loading mechanism 7 performs stress control, displacement control and strain control on the sample through the loading rod 8.
[0018] The specific usage process is as follows: I. Sample Preparation and Pretreatment: 1) Select typical marine engineering titanium alloy (such as Ti-6Al-4V) plates and process them into cross-shaped biaxial tensile specimens by wire cutting. The working area of the specimen is 1-5mm thick to facilitate the penetration of X-rays. 2) Pre-fabricate a microcrack with a length of approximately 100-500 μm in the center of the working area of the sample; 3) Perform standard metallographic grinding and polishing on the sample surface, and ultrasonically clean it with acetone and anhydrous ethanol. After drying, it is ready for use.
[0019] II. System Installation and Calibration: 1) Install the pre-cracked titanium alloy specimen on the specimen fixture, ensuring that the center of the specimen coincides with the center of the chamber and the center of the X-ray path; 2) Pre-tighten each loading shaft to eliminate gaps; 3) Inject seawater solution into the seawater environment tank through the water inlet until the sample is completely submerged; 4) Using a three-dimensional adjustment platform, the tip of the microcrack on the sample is precisely adjusted to the focal position of the synchrotron X-ray beam.
[0020] III. Experimental Parameter Settings and Synchronization: 1) Setting up the mechanical loading device: The dual-axis loading path is set through the control system, including displacement control, strain control, and load control; 2) Synchrotron Radiation and Detection Settings: The synchrotron X-ray energy was set to 35 keV to achieve good penetration of the titanium alloy. The beam size was adjusted to 50 μm (V) × 200 μm (H) to accurately cover the deformation zone at the crack tip. The detector acquisition mode was set to acquire a diffraction pattern every 60 seconds.
[0021] IV. In-situ Testing and Data Acquisition: 1) Start the servo loading mechanism and apply a biaxial load to the sample according to the preset path; 2) Simultaneously start the detector to collect data and continuously record load, displacement, environmental parameters, and X-ray diffraction patterns; 3) During the experiment, when the crack begins to propagate or corrosion products form inside the crack and at the tip, the detector will collect diffraction rings or diffraction spots of the titanium alloy matrix and corrosion products (such as TiO2). 4) The experiment continues until the crack extends to the predetermined length or a significant corrosion product signal is detected.
[0022] V. Data Processing and Analysis: The acquired two-dimensional diffraction pattern is integrated to convert it into a one-dimensional diffraction pattern that varies with time (intensity versus diffraction vector Q or 2). (relationship curve) 2) Perform qualitative and quantitative phase analysis on the diffraction pattern to identify and calculate the relative content of the titanium alloy matrix and each corrosion product phase with time or strain. 3) Correlate phase evolution data with macroscopic mechanical curves to comprehensively analyze the interaction mechanism between stress level, crack propagation behavior and corrosion product formation.
[0023] Therefore, this invention employs a biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction to achieve in-situ characterization and analysis of corrosion product evolution at cracks under near-service conditions of complex stress and seawater corrosion environment, providing technical support for revealing the microcrack corrosion failure mechanism of marine materials under near-service conditions.
[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction, characterized in that: It includes a radiation generator, and along the optical path of the radiation generator, a slit, a mechanical loading device, and a detector are arranged in sequence; a seawater environment tank is arranged in the center of the mechanical loading device, and a three-dimensional adjustment platform is arranged below the mechanical loading device.
2. The biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction according to claim 1, characterized in that: The radiation generator specifically adopts a synchrotron radiation X-ray emission source, which is a high-intensity, high-collimation synchrotron radiation source, and the generated X-ray energy range is 30-80keV; The beam size is adjusted to the micrometer level through a slit to meet the experimental requirements of different fields of view. The detector has high spatial resolution and high frame rate acquisition capability, and can capture transient diffraction signals generated by the dynamic process of the test.
3. The biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction according to claim 1, characterized in that: The three-dimensional platform uses a screw or servo motor to achieve adjustment of the XYZ three-axis degrees of freedom for the mechanical loading device.
4. The biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction according to claim 1, characterized in that: The structure of the seawater environment tank in the mechanical loading device is as follows: The seawater environment tank adopts an octagonal structure. The top of the seawater environment tank is provided with a water inlet and the bottom is provided with a drain outlet. Seawater is injected and discharged through the water inlet and the drain outlet. A loading hole is provided at 90-degree intervals on the outside of the seawater environment tank. A follow-up sealing structure is provided on the outside of the four loading holes. The front and back of the seawater environment tank are provided with high-transmittance transparent windows. The high-transmittance transparent windows are fixed to the seawater environment tank by flanges.
5. The biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction according to claim 4, characterized in that: The seawater environment tank is made of corrosion-resistant titanium alloy. The water inlet and drain hole are sealed by flanges. The high-transmittance transparent window is made of sapphire glass. The follow-up sealing device is made of multi-layer rubber composite material.
6. The biaxial mechanical loading device for seawater environment based on synchrotron X-ray diffraction according to claim 4, characterized in that: The mechanical loading device has the following structure: it includes two fixed surfaces, and four servo loading mechanisms are arranged between the two fixed surfaces. The adjacent servo loading mechanisms are spaced 90 degrees apart. Each servo loading mechanism has a loading rod and a sample clamp arranged at its end. The loading rod and the sample clamp extend into the seawater environment tank through the loading hole. The sample clamp is responsible for fixing the test sample. The servo loading mechanism performs stress control, displacement control and strain control on the sample through the loading rod.