Water-swelling material and method for preventing processing cracks of through hole of fragile material

Abstract

The invention discloses a water-swelling material and a method for preventing processing cracks of through holes of a brittle material, and relates to the field of precision processing of brittle materials, the water-swelling material comprises water-swelling rubber and silica powder particles, and the mass of the silica powder particles is 10-20% of the mass of the water-swelling rubber; the silica powder particles are pretreated by a silane coupling agent; and mixing the silica powder particles with the water-absorbing expansion rubber, so that the silica powder particles are uniformly dispersed in the water-absorbing expansion rubber to obtain the water-absorbing expansion material. The water-absorbing expansion material has large water swelling rate, has high strength after absorbing water and effectively supports the upper portion of the hole wall of the through hole, and cracks, caused by axial cutting force, of the through hole are avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of precision machining of brittle materials, and in particular relates to a water-swelling material and a method for preventing cracks in machining intersecting holes of brittle materials. Background Art

[0002] Precision optical parts are generally made of brittle materials such as quartz glass and microcrystalline glass. In particular, precision parts such as laser optical resonators require a series of high-precision interconnected holes to be machined inside the above brittle materials, which requires the machining of orthogonal or other angled intersecting holes. When machining intersecting holes on brittle materials, due to the brittleness of the material, cracks are easily formed on the upper part of the intersection of the intersecting holes, such as Figure 1 As shown, 1 is a crack, 2 is an intersecting hole, and 3 is a brittle material matrix. These cracks may form excess materials due to crack expansion and material collapse during subsequent use, causing serious reliability problems; the capillary structure of tiny cracks on the surface is also easy to adhere to or retain various pollutants and is not easy to remove. During the long-term operation of the instrument device, the polluted impurities are slowly released, resulting in the performance of the instrument device system being reduced, affecting its long-term working stability.

[0003] In order to prevent the occurrence of cracks and reduce the size of cracks, two measures are currently used:

[0004] On the one hand, during the processing, the tool structure is optimized, the cutting parameters are reduced, and the tool is replaced early (to ensure the tool is sharp) to reduce the cutting force, thereby minimizing the cracks as much as possible, but this will lead to reduced production efficiency and increased production costs (ex ante control); on the other hand, after the intersecting holes are processed, various finishing methods are used to repair the cracked areas, especially for high-demand optical chambers, and individual fine positions have to rely on manual operations. These inevitably lead to an increase in processing time or processing steps, further reducing processing efficiency (ex post processing).

[0005] From the above, it can be seen that in the existing technical solutions, the pre-control measures have limited effects, resulting in reduced processing efficiency; post-processing increases the workload of finishing, further reducing production efficiency. Summary of the invention

[0006] The technical problem solved by the present application is: to overcome the deficiencies of the prior art and provide a method for preventing cracks in intersecting hole processing of brittle materials by using water-swellable materials; based on the water-swelling characteristics of the water-swellable materials, the material is pre-buried in the processed hole at the position where the intersecting hole is to be formed before the intersecting hole is processed, so as to achieve effective support above the hole wall, thereby avoiding the generation of cracks in the intersecting hole caused by axial cutting force, without the need to reduce processing parameters, thereby ensuring processing efficiency; after the intersecting hole is processed, the water-swellable material is dried and shrunk, and the water-swellable support material can be removed.

[0007] The technical solutions provided by this application are as follows:

[0008] In a first aspect, a water-swellable material is provided, comprising water-swellable rubber and silicon micropowder particles, wherein the mass of the silicon micropowder particles is 10 to 20% of the mass of the water-swellable rubber; the silicon micropowder particles are pretreated with a silane coupling agent; the silicon micropowder particles and the water-swellable rubber are mixed so that the silicon micropowder particles are evenly dispersed in the water-swellable rubber to obtain the water-swellable material.

[0009] In one possible implementation of the water-swellable material, the pretreatment step includes: preparing a silane coupling agent, deionized water, and anhydrous ethanol, adding silicon micropowder particles, stirring, filtering, taking out, drying, grinding, and pulverizing to obtain pretreated silicon micropowder particles.

[0010] In one possible implementation of the water-swellable material, the silane coupling agent is KH-570.

[0011] In one possible implementation of the water-swellable material, the mass ratio of the silane coupling agent, deionized water, and anhydrous ethanol is 5:3-7:88-92.

[0012] In one possible implementation of the water-swellable material, the diameter of the silicon micropowder particles is 40-50 μm.

[0013] In a second aspect, a method for preventing cracks in intersecting hole processing of brittle materials by using a water-swellable material is provided, which is used in the intersecting hole processing process of an optical brittle material substrate, wherein the intersecting hole includes a D1 hole and a D2 hole, one end of the D2 hole is connected to the D1 hole, the diameter of the D1 hole is D1, and the diameter of the D2 hole is D2;

[0014] Processing methods include:

[0015] Prefabricate any of the above-mentioned water-swellable materials into a water-swellable mandrel, wherein the diameter of the water-swellable mandrel is smaller than the diameter of the D1 hole, and the length of the water-swellable mandrel is greater than the diameter of the D2 hole;

[0016] After the optical brittle material substrate has been processed with the D1 hole but before the D2 hole has been processed, the water-absorbing and swelling mandrel is inserted into the D1 hole and the water-absorbing and swelling mandrel is aligned with the processing position of the D2 hole to obtain an assembly;

[0017] The assembly is immersed in water. After it fully absorbs water and expands, a D2 hole is processed on the optical brittle material substrate. After the D2 hole is processed, it is left to dry. After the water-swelling mandrel loses water and shrinks, it is removed.

[0018] The diameter of the water-swellable core shaft is (D1-0.2) mm.

[0019] The length of the water-swellable core shaft is L=3D2.

[0020] In summary, this application at least includes the following beneficial technical effects:

[0021] Ceramic microspheres are added to the water-swelling material to enhance its toughness and support capacity, and a pre-supported processing anti-cracking method is designed to reduce the geometric size of the cracks without lowering the cutting parameters in advance and reducing the actual use time of the tool, thereby improving production efficiency. The geometric size of the cracks is greatly reduced, the subsequent finishing workload is reduced, and subsequent finishing work can even be completely avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of cracks generated by intersecting holes in brittle materials;

[0023] Figure 2 This is a schematic diagram of the embedded water-absorbing and expanding material.

[0024] Explanation of the accompanying figures: 2. Intersecting hole; 3. Optically brittle material matrix; 4. Water absorption and expansion mandrel. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] The present invention relates to a water-swelling material and its application in the processing of brittle materials, and in particular to an application for preventing cracks from being generated in the processing of intersecting holes of brittle materials. The present invention aims at the problem that when processing intersecting holes on brittle optical glass materials, cracks are easily formed at the upper intersection of the intersecting holes due to the brittleness of the materials, and provides a method for preventing cracks from being generated or reducing the size of cracks.

[0027] The present application discloses a method for preventing cracks in intersecting holes of brittle materials by using water-swellable materials, such as Figure 2 As shown, the following steps are included:

[0028] A material with a relatively hard material and strong supporting effect after water swelling is prepared, the water swelling ratio is greater than 300%, and the tensile strength is ≥8MPa. The main component of the material is high-strength water-swelling rubber. In order to ensure that the material can maintain a high supporting strength after water absorption, 10-20% of silicon micropowder particles with a diameter of 40-50μm are added to the high-strength water-swelling rubber. At the same time, in order to ensure that the silicon micropowder particles added to the material after water swelling have a good bonding force with the main material, the surface of the silicon micropowder particles needs to be pretreated before adding. The silicon micropowder surface treatment method uses silane coupling agent KH-570. The surface treatment process is: KH-570, deionized water, and anhydrous ethanol are prepared in a mass ratio of 5:3-7:88-92, silicon micropowder particles are added and magnetically stirred in 80-degree constant temperature water for 1h, filtered out and dried in a 100-degree drying oven for 1h, and surface-treated silicon micropowder is obtained after grinding and crushing. The surface pretreated silicon micropowder is mixed with the water-swelling rubber by a double-roll mill, so that the silicon micropowder particles are evenly dispersed in the water-swelling rubber to obtain the reinforced water-swelling rubber.

[0029] like Figure 2 As shown, a water-swelling mandrel 4 is prefabricated according to the size of the first processed hole, namely, the D1 hole. The diameter of the water-swelling mandrel 4 is (D1-0.2) mm, and the length L=3D2. The water-swelling mandrel 4 is inserted into the corresponding position before the D2 hole of the optical brittle material substrate 3 is processed after the D1 hole of the intersecting hole 2 is processed, and immersed in water to fully absorb water and expand (more than 30 minutes) to ensure reliable fit and support before processing the D2 hole. After the D2 hole is processed, it is left to dry for more than 1 hour, and the water-swelling mandrel 4 is removed after it loses water and shrinks.

[0030] principle:

[0031] The main reason for the cracks in the intersecting hole processing of brittle materials is that when the intersecting holes are processed to the end, when they are about to be intersected, the lack of support at the bottom of the hole and the brittleness of the material lead to cracks in the relevant area. Figure 2 As shown in the figure, a water-swelling material smaller than hole D1 is prefabricated and embedded under the intersecting hole before processing. After sufficient water absorption and expansion to reach the supporting strength, the D2 hole is processed to achieve effective support above the hole wall, thereby avoiding the generation of intersecting hole cracks caused by axial cutting force. After the intersecting hole is processed, the water-swelling material is dried and shrunk, and the water-swelling support material can be removed.

[0032] Effective support is achieved above the intersecting hole wall of the intersecting hole, thereby avoiding the generation of intersecting hole cracks caused by axial cutting force or reducing the crack geometric size as much as possible without reducing processing parameters and manual repair methods, thereby ensuring processing efficiency; after the intersecting hole is processed, the water-swelling support material can be taken out through drying and shrinkage of the water-swelling material.

[0033] While effectively controlling the generation of cracks, it does not increase excessive auxiliary time and has little impact on processing efficiency.

[0034] Example 1

[0035] A water-swelling material includes water-swelling rubber and silicon micropowder particles, wherein the mass of the silicon micropowder particles is 10% of the mass of the water-swelling rubber, and the diameter of the silicon micropowder particles is 40 to 50 μm. The silicon micropowder particles undergo the following pretreatment process: KH-570, deionized water, and anhydrous ethanol are prepared in a mass ratio of 5:3 to 7:88 to 92, silicon micropowder particles are added and magnetically stirred in a constant temperature water area of ​​80 degrees for 1 hour, filtered out and dried in a drying oven at 100 degrees for 1 hour, and ground and crushed to obtain surface-treated silicon micropowder. The silicon micropowder particles are mixed with the water-swelling rubber to uniformly disperse the silicon micropowder particles in the water-swelling rubber to obtain a water-swelling material.

[0036] Example 2

[0037] The only difference from Example 1 is that the mass of the silicon micropowder particles is 15% of the mass of the water-swellable rubber.

[0038] Example 3

[0039] The only difference from Example 1 is that the mass of the silicon micropowder particles is 20% of the mass of the water-swellable rubber.

[0040] Comparative Example 1

[0041] The only difference from Example 1 is that the silicon micropowder particles are not pretreated with a silane coupling agent.

[0042] Comparative Example 2

[0043] The only difference from Example 1 is that a water-swellable material only includes water-swellable rubber without adding silicon micropowder particles.

[0044] Comparative Example 3

[0045] The only difference from Example 1 is that the mass of the silicon micropowder particles is 30% of the mass of the water-swellable rubber.

[0046] Comparative Example 4

[0047] The only difference from Example 1 is that the particle size of the silicon micropowder particles is 60-70 μm.

[0048] The water-swellable materials obtained in the above examples and comparative examples were tested to obtain their properties after water absorption, as shown in Table 1 below.

[0049] Table 1 Test results of water-swelling materials

[0050]

[0051]

[0052] According to Examples 1-3, it can be seen that as the content ratio of silicon micropowder particles increases, the water expansion ratio of the water-swellable material after absorbing water decreases, and the compressive strength and tensile strength increase. Compared with Comparative Example 2, Examples 1-3 show that with the addition of silicon micropowder particles, the compressive strength and tensile strength of the water-swellable material after absorbing water increase, which improves the supporting effect of the water-swellable material on the intersecting holes. Compared with Comparative Example 3, it can be seen that when the amount of silicon micropowder particles added exceeds the range specified in this patent, the spacing between the silicon micropowder particles becomes smaller, resulting in uneven dispersion of the silicon micropowder particles, resulting in an increase in defects in the matrix material, a decrease in compressive strength and tensile strength, and a reduction in the supporting effect. In addition, the water expansion ratio is reduced, which does not meet the minimum requirement of 300%, which is not conducive to the water-swellable material fully fitting with the supporting tube wall after absorbing water and swelling.

[0053] Compared with Comparative Example 1, Examples 1-3 do not perform pretreatment with silane coupling agent. The compressive strength and tensile strength of Comparative Example 1 are reduced, the surface of the silicon micropowder particles is smooth, and the interface layer with the water-swelling rubber matrix is ​​clear, indicating that the bonding between the silicon micropowder particles and the water-swelling rubber matrix is ​​poor, resulting in reduced compressive strength and tensile strength.

[0054] Compared with Comparative Example 4, in Examples 1-3, when the diameter of the silicon micropowder particles is less than 40-50 μm, they are easy to agglomerate; when the diameter of the silicon micropowder particles is larger (taking Comparative Example 4 as an example), ... the water expansion ratio is reduced, and the mixing fluidity of the components is deteriorated during physical blending, and segregation and stratification are prone to occur, resulting in reduced compressive strength and tensile strength.

[0055] When the water-swelling material is used in the process of processing the intersecting holes of the optically brittle material matrix, the smaller the diameter of the D1 hole, the less silicon micropowder particles should be added to the water-swelling material, and the increase in the linear expansion coefficient is conducive to the water-swelling material to fully fit with the support tube wall after swelling. For example: when the diameter of the D1 hole is 1.5-3mm, the mass of the silicon micropowder particles is 10-12% of the mass of the water-swelling rubber.

[0056] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0057] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A water-swellable material, characterized in that: The invention comprises water-swelling rubber and silicon micropowder particles, wherein the mass of the silicon micropowder particles is 10-20% of the mass of the water-swelling rubber; the silicon micropowder particles are pretreated with a silane coupling agent; the silicon micropowder particles are mixed with the water-swelling rubber to make the silicon micropowder particles uniformly dispersed in the water-swelling rubber, thereby obtaining the water-swelling material.

2. The water-swellable material according to claim 1, characterized in that: The pretreatment step includes: preparing a silane coupling agent, deionized water and anhydrous ethanol, adding silicon micropowder particles, stirring, filtering, taking out, drying, grinding and crushing to obtain pretreated silicon micropowder particles.

3. A water-swellable material according to claim 2, characterized in that: The silane coupling agent is KH-570.

4. The water-swellable material according to claim 1, characterized in that: The mass ratio of the silane coupling agent, deionized water and anhydrous ethanol is 5:3-7:88-92.

5. The water-swellable material according to claim 1, characterized in that: The diameter of the silicon micropowder particles is 40 to 50 μm.

6. A method for preventing cracks in intersecting holes of brittle materials by using water-swellable materials, characterized in that: A process for processing an intersecting hole (2) of an optically brittle material substrate (3), wherein the intersecting hole comprises a D1 hole and a D2 hole, one end of the D2 hole is connected to the D1 hole, the diameter of the D1 hole is D1, and the diameter of the D2 hole is D2; Processing methods include: The water-swellable material according to any one of claims 1 to 3 is prefabricated into a water-swellable mandrel (4), wherein the diameter of the water-swellable mandrel (4) is smaller than the diameter of the hole D1, and the length of the water-swellable mandrel (4) is greater than the diameter of the hole D2; After the optical brittle material substrate (3) has processed the D1 hole but before processing the D2 hole, the water-absorbing and swelling mandrel (4) is inserted into the D1 hole so that the water-absorbing and swelling mandrel faces the processing position of the D2 hole, thereby obtaining a combined component; The assembly is immersed in water, and after it fully absorbs water and expands, a D2 hole is processed on the optical brittle material substrate (3). After the D2 hole is processed, it is left to dry, and the water-swelled mandrel (4) is removed after it loses water and shrinks.

7. A method for preventing cracks in intersecting holes of brittle materials by using water-swellable materials according to claim 6, characterized in that: The diameter of the water-swellable core shaft (4) is (D1-0.2) mm.

8. The method of preventing cracks in intersecting holes of brittle materials by using water-swellable materials according to claim 6, characterized in that: The length L of the water-swellable core shaft (4) is 3D2.

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