A surface modification method for improving the room temperature ductility of iron-based amorphous alloys

Abstract

The application discloses a surface modification method for improving the room temperature plasticity of iron-based amorphous alloy, and belongs to the field of material surface modification. Specifically, the method is characterized by shot blasting treatment on the surface of the iron-based amorphous alloy to improve and enhance the room temperature plasticity of the iron-based amorphous alloy, in view of the characteristics of high strength and low room temperature plasticity of the iron-based amorphous alloy. The basic process comprises the following steps: in the first step, fluxing purification technology and J-quenching technology are applied to prepare the iron-based amorphous alloy required by the experiment; and in the second step, an automatic control (numerical control) shot blasting equipment is used to perform shot blasting treatment on the surface of the amorphous alloy, so that the surface modified iron-based amorphous alloy is obtained. The application has the following advantages: 1. The equipment is simple, the operation is convenient, the cost is low, the economy is efficient, there is no three waste emissions, and the application has the potential for large-scale popularization and application; 2. The room temperature compression plasticity deformation capacity is significantly improved, and can be increased by more than 2 to 8 times. The application is mainly used for preparing the iron-based amorphous alloy with high strength and good room temperature plasticity.

Description

Technical Field

[0001] The invention belongs to the field of material surface modification, and in particular relates to a surface modification method for improving the room temperature plasticity of an iron-based amorphous alloy. Background Art

[0002] In the past decade, iron-based amorphous alloys have attracted much attention due to their excellent properties such as strength, elastic deformation and magnetism. Iron-based amorphous alloys not only have broad application prospects in nuclear materials, mechanical manufacturing, medical devices, semiconductor materials and chemical materials, but also can open up new research directions in related disciplines and provide new opportunities and ways to solve major scientific problems.

[0003] While iron-based amorphous alloys possess many unique properties, they also suffer from a fatal weakness: strain softening. Unlike traditional crystalline materials, iron-based amorphous alloys lack crystalline defects such as dislocations and stacking faults. Their plastic deformation is primarily controlled by the generation and proliferation of shear bands, exhibiting highly localized characteristics. This directly leads to the lack of macroscopic plasticity in amorphous alloys at room temperature, limiting their application as structural and functional materials. Therefore, improving the room-temperature plasticity of iron-based amorphous alloys is of great academic significance and application value. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing iron-based amorphous alloy has very poor room temperature plasticity, and to provide a surface modification method for improving the room temperature plasticity of the iron-based amorphous alloy.

[0005] A surface modification method for improving the room temperature plasticity of an iron-based amorphous alloy is characterized in that the method obtains an iron-based amorphous alloy with both high strength and good room temperature plasticity by shot peening the surface of the iron-based amorphous alloy, and the room temperature plasticity can be improved by as much as 8 times.

[0006] The iron-based amorphous alloy is a ternary Fe 80 P 13 C7 amorphous alloy, quaternary Fe 50 Ni 30 P 13 C7 amorphous alloy and hexavalent Fe 74 Si3B4P 10 C4Mo5 amorphous alloy.

[0007] A surface modification method for improving the room temperature plasticity of an iron-based amorphous alloy is specifically carried out in the following steps:

[0008] Step 1: Prepare the iron-based amorphous alloy required for the experiment through fluxing purification technology and J-quenching technology;

[0009] Step 2: Determine the target shot peening intensity and other shot peening parameters according to the sample size specifications and performance requirements;

[0010] Step 3: Check the process before shot blasting to ensure that it is in place and clamp the sample;

[0011] Step 4: Shot peening the sample according to the process parameter requirements;

[0012] Step 5: After shot peening is completed, remove the sample from the fixture and inspect the sample after shot peening to ensure that there are no broken projectiles embedded in the surface, no bumps and scratches, and the surface coverage meets the requirements;

[0013] Step 6: Cut the shot-peened amorphous sample into a specimen with an aspect ratio of 2:1, and use a universal testing machine to measure the mechanical properties of the specimen, including the yield strength σ y , fracture strength σ f and compression plasticity ε p .

[0014] The shot peening process of iron-based amorphous alloy adopts practical and effective relevant process parameters, such as the type of shot peening medium, the size of the shot peening medium, the shot peening time, the shot peening intensity, the shot peening coverage, and the distance between the shot peening machine nozzle and the sample surface. Therefore, all process parameters in the shot peening process should be controlled within a reasonable range to achieve the best shot peening modification effect.

[0015] When performing shot peening in the invention, the air pressure is controlled to be 0.1MPa~0.4MPa, the distance from the shot peening machine nozzle to the sample surface is 100mm~150mm, the shot peening medium is glass shot (the shot material specifications are selected with reference to HB / Z 26-2011), the shot size specifications are BZ10 (100μm), BZ15 (150μm) and BZ20 (200μm), the shot spray angle is 90°, the shot peening time is about 20s~1min, the shot peening intensity is about 0.15mmA~0.30mmA, and the shot peening coverage is 100%.

[0016] The effectiveness of shot peening surface treatment is primarily characterized by the peening intensity. If the peening intensity is too low, the residual compressive stress introduced will be small, failing to achieve the desired modification effect. If the peening intensity is too high, microcracks may form on the specimen surface, leading to a relaxation or redistribution of the residual stress field, similarly failing to achieve the desired modification effect. The choice of shot peening process parameters directly determines the actual peening quality and effect, so all process parameters during the shot peening process should be controlled within a reasonable range.

[0017] The application has the following advantages: (1) simple equipment. The surface performance of the iron-based amorphous alloy can be improved by automatic control (numerical control) shot blasting equipment. (2) Performance can be controlled. By optimizing the shot blasting process parameters, the microstructure and residual stress field of the amorphous alloy are controlled, so as to meet the differentiated performance requirements in actual engineering applications. (3) Batch production. The method is low in cost, simple in operation, high in economy, and free of three wastes, and can meet the batch production demand of industrial application.

[0018] Effects of the application: The plasticizing effect of the surface modification method for improving the room temperature plasticity of the iron-based amorphous alloy is very obvious. For example, the plastic deformation of Fe 80 P 13 C7 amorphous alloy can be increased to about 3.2%, and the increase value can be more than 8 times. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the X-ray diffraction spectrum of the as-cast untreated Fe 80 P 13 C7 amorphous alloy sample (labeled as Comparative Example 1) and the shot blasting treated Fe

[0020] Figure 2 is the stress-strain curve of Comparative Example 1 and Example 1;

[0021] Figure 3 is the SEM image of the side shear band of Comparative Example 1;

[0022] Figure 4 is Figure 3 the enlarged view of the A area;

[0023] Figure 5 is the SEM image of the side shear band of the surface modified Fe 80 P 13 C7 amorphous alloy sample of Example 1;

[0024] Figure 6 is Figure 5 the enlarged view of the A area;

[0025] Figure 7 is the stress-strain curve of the as-cast untreated Fe 50 Ni 30 P 13 C7 amorphous alloy sample (labeled as Comparative Example 2) and the shot blasting treated Fe

[0026] Figure 8 is the stress-strain curve of the as-cast untreated Fe 74 Si3B4P 10Comparative stress-strain curves of the C4Mo5 amorphous alloy sample in the as-cast state without treatment (numbered as comparative example 3) and after shot peening treatment (numbered as example 3). DETAILED DESCRIPTION

[0027] The present invention provides a surface modification method for improving the room temperature plasticity of an iron-based amorphous alloy. By shot peening the surface of the iron-based amorphous alloy, the room temperature plasticity of the iron-based amorphous alloy can be improved by as much as 8 times. The present invention is further described in detail below with reference to embodiments and accompanying drawings.

[0028] Example 1

[0029] Fe 80 P 13 The C7 ternary iron-based amorphous alloy specimens were shot peened using an automatic control (CNC) shot peening equipment. The process parameter requirements were as follows: the shot peening medium was glass shot, the shot peening time was 30s, the shot peening intensity was approximately 0.15mmA, the shot peening coverage was 100%, the air pressure was 0.2MPa, and the shot injection angle was 90°. The treated amorphous alloy specimens were subjected to compression plasticity testing using a universal testing machine.

[0030] Example 2

[0031] Fe 50 Ni 30 P 13 The C7 quaternary iron-based amorphous alloy specimens were shot peened using an automatic control (CNC) shot peening equipment. The process parameter requirements were as follows: the shot peening medium was glass shot, the shot peening time was 30s, the shot peening intensity was approximately 0.15mmA, the shot peening coverage was 100%, the air pressure was 0.2MPa, and the shot injection angle was 90°. The treated amorphous alloy specimens were subjected to compression plasticity testing using a universal testing machine.

[0032] Example 3

[0033] Fe 74 Si3B4P 10 The C4Mo5 hexa-element iron-based amorphous alloy specimens were shot peened using an automatic (numerical control) shot peening equipment. The process parameters required were as follows: the shot peening medium was glass shot, the shot peening time was 30 s, the shot peening intensity was approximately 0.20 mmA, the shot peening coverage was 100%, the air pressure was 0.3 MPa, and the shot injection angle was 90°. The treated amorphous alloy specimens were then subjected to compression plasticity testing using a universal testing machine.

[0034] The above is a description of the preferred embodiments of the present invention. It should be noted that the present invention is not limited to the above embodiments. Various modifications may be made to the present invention as long as they meet the scope requirements of the claims, detailed description of the invention, and drawings, and all such modifications fall within the scope of the present invention.

Claims

1. A surface modification method for improving the room temperature plasticity of an iron-based amorphous alloy, characterized in that: The method is to shot peen the surface of the iron-based amorphous material, and is specifically carried out in the following steps: (1) Prepare iron-based amorphous alloys through fluxing purification technology and J-quenching technology; (2) performing shot peening on the surface of the iron-based amorphous alloy to obtain a surface-modified iron-based amorphous alloy; During the shot blasting process in step (2), the air pressure is controlled to be 0.1-0.4 MPa; The shot peening time in step (2) is about 20 seconds to 1 minute; During the shot peening process described in step (2), the shot velocity is controlled to be 60-100 m / s; During the shot peening process described in step (2), the distance between the shot peening machine nozzle and the surface of the iron-based amorphous alloy sample is 100 mm to 150 mm; The shot blasting medium used in the shot blasting process described in step (2) is glass shot, and the shot specifications are selected with reference to HB / Z26-2011, and the size specifications of the shot are 100 μm, 150 μm and 200 μm; During the shot peening process in step (2), the shot spraying angle is 90°, the shot peening intensity is 0.15 mmA to 0.30 mmA, and the shot peening coverage is 100%; The iron-based amorphous alloy is a ternary Fe 80 P 13 C7 amorphous alloy, quaternary Fe 50 Ni 30 P 13 C7 amorphous alloy and hexavalent Fe 74 Si3B4P 10 C4Mo5 amorphous alloy.

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