High-wear-resistance easy-to-process ceramic chopper and preparation method thereof

Abstract

The invention discloses a high-wear-resistance easy-to-process ceramic chopper and a preparation method thereof, and relates to the technical field of ceramic choppers. The ceramic chopper comprises a chopper body, a welding nozzle and a wire passing through hole, wherein the wire passing through hole extends to an inner chamfer of the welding nozzle in the longitudinal axis direction of the chopper body; the chopper body is composed of a first sintering body and a second sintering body, and the first sintering body surrounds the second sintering body. The preparation method of the ceramic chopper comprises the following steps: uniformly mixing a binder with first sintered body ceramic powder and second sintered body ceramic powder to obtain a first sintered body feed and a second sintered body feed; and then forming, sintering and grinding the first sintering body feed and the second sintering body feed to obtain the ceramic chopper. By the adoption of the method, the ceramic chopper with the first sintering body high in hardness and abrasion resistance and the second sintering body high in toughness and easy to machine can be obtained, the service life of the ceramic chopper is greatly prolonged, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic splitting knives, and in particular to a highly wear-resistant and easy-to-process ceramic splitting knives and a preparation method thereof. Background Art

[0002] The welding ceramic splitter, also known as ceramic capillary or ceramic nozzle, is a high-precision axisymmetric ceramic welding tool with micro-pores, and is a precision micro-pore structure ceramic component.

[0003] High-density fine-grained alumina is the main material for ceramic splitters due to its excellent wear resistance, oxidation resistance and easy cleaning ability. However, due to its extremely high hardness and wear resistance, high-purity alumina will bring a series of problems to fine processing. For example, 99% alumina has high wear resistance and brittleness. During the grinding process of the inner hole of the splitter, there will be problems such as low grinding efficiency and easy collapse of the inner hole, which will lead to low production efficiency, serious loss of grinding consumables and low yield rate.

[0004] To solve this problem, existing ceramic splitters add ZrO to the original alumina. 2 Cr 2 O 3 Add ZrO 2 The purpose is to use zirconium oxide to toughen alumina and make its microstructure more compact, thereby reducing the brittleness of alumina and making it easier to process, making it less likely to have problems such as chipping and fracture during processing. 2 O 3 The purpose is to increase the density of the ceramic splitter, reduce the grain size, and reduce the brittleness, thereby giving the ceramic splitter excellent compression resistance, bending resistance, and easy processing capabilities. However, the addition of these two substances will affect the performance parameters of the ceramic splitter, such as hardness, elastic modulus, and fracture toughness, thereby reducing the service life of the ceramic splitter, increasing the number of replacement times for the ceramic splitter, and reducing production efficiency.

[0005] The existing ceramic splitter production process is: using 0.5% to 2% Cr 2 O 3 5% to 20% ZrO 2 and 78-95% Al 2 O 3 The powder is mixed with a binder to form a granule or spray granule, and then injection molding or dry pressing is performed, and finally sintered into porcelain and finely processed to obtain a finished product. The ceramic splitter obtained by this method has low wear resistance on the welding end surface, a short service life, and a high number of replacements. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a highly wear-resistant and easy-to-process ceramic splitting knife and a preparation method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a highly wear-resistant and easy-to-process ceramic splitting knife, the ceramic splitting knife comprising a splitting knife body, a welding nozzle and a wire through hole, the wire through hole extending along the longitudinal axis direction of the splitting knife body to the inner chamfer of the welding nozzle; the splitting knife body is composed of a first sintered body and a second sintered body, the first sintered body is arranged around the second sintered body;

[0009] The material of the ceramic splitting knife is Cr 2 O 3 、ZrO 2 and Al 2 O 3 composition, wherein the material composition of the first sintered body is Al 2 O 3 The content of Al in the material composition of the second sintered body is greater than 2 O 3 The content.

[0010] The second sintered body contains a large amount of ZrO 2 and Cr 2 O 3 As a result, the grain size becomes smaller during the sintering process, the density of the ceramic splitting tool increases, and the brittleness decreases, thus giving the ceramic splitting tool excellent compression and bending resistance, preventing it from breaking due to high impact or high pressure during finishing or welding.

[0011] The first sintered body contains a large amount of Al 2 O 3 , so that the splitting knife has high hardness and high wear resistance, and improves the service life of the ceramic splitting knife.

[0012] The present invention not only meets the use requirements of high hardness and high wear resistance of the end face of the splitter by combining the first sintered body and the second sintered body, but also overcomes the defects of easy breakage and chipping during the use of the splitter, and makes the grinding of the inner hole of the splitter more efficient and convenient. In the ceramic splitter prepared by the present invention, during the forming and sintering process, the two sintered bodies are welded together without a dividing line, so that the two are firmly combined and the first sintered body located on the outer layer is not easy to fall off; if a wear-resistant layer is prepared on the surface of the splitter by co-firing, spraying, deposition, etc., the thickness of the wear-resistant layer that can be prepared is limited, and the bonding force is also poor, it is not impact-resistant, and it is easy to crack and fall off, resulting in poor stability and concentration.

[0013] Preferably, the material composition of the first sintered body includes the following components: 0.2% to 0.5% by weight of Cr 2 O3 2% to 5% ZrO 2 , 94.5%~97.8% Al 2 O 3 ;

[0014] The material composition of the second sintered body includes the following components: 2% to 6% by weight of Cr 2 O 3 10% to 20% ZrO 2 , 74%~88% Al 2 O 3 .

[0015] In the first sintered body, if ZrO 2 and Cr 2 O 3 The content is too high, that is, Al in the composition 2 O 3 If the content is too low, the first sintered body will have high toughness after sintering, but at the same time it will lead to low hardness and poor wear resistance of the first sintered body, which cannot achieve the purpose of increasing the service life of the ceramic splitter. 2 and Cr 2 O 3 The content is too low, that is, Al 2 O 3 If the content is too high, the first sintered body can have high hardness and high wear resistance, but at the same time, the first sintered body has poor toughness and high brittleness. During the finishing process, the high hardness makes it difficult to process the outer surface of the splitting tool and the welding end face, and the high brittleness makes it easy to cause internal hole collapse and breakage of the splitting tool during the processing and subsequent welding use.

[0016] In the second sintered body, if ZrO 2 and Cr 2 O 3 The content is too high, that is, Al in the composition 2 O 3 If the content is too low, the second sintered body has high toughness after sintering, but low hardness and poor wear resistance. During the welding process, the welding wire passes through the wire through hole of the splitter and contacts the inner layer, which can easily cause the inner layer to wear, resulting in an increase in the diameter of the inner hole or an increase in the roughness of the inner hole, thereby causing the welding wire to be damaged or even broken. It can also cause changes in the size of the welding end face (such as larger chamfers and elliptical shapes), poor welding stability, and affect the welding quality. Defects such as cold welding and loose welding may occur. If scratches or pits are produced, problems such as wire breakage and warping may easily occur during welding. If ZrO 2 and Cr 2 O 3 The content is too low, that is, Al 2 O 3If the content is too high, the second sintered body can have high hardness and high wear resistance, but at the same time the second sintered body has poor toughness and is too brittle. During the fine processing, it is difficult to process the through hole of the splitting cutter, and the splitting cutter is easily broken during the processing and subsequent welding process.

[0017] Therefore, the present invention, by setting a reasonable composition of the first sintered body and the second sintered body, not only meets the use requirements of high hardness and high wear resistance of the end face of the splitter, but also overcomes the defects of easy breakage and chipping during the use of the splitter, and also makes the grinding of the inner hole of the splitter more efficient and convenient.

[0018] Preferably, the thickness of the first sintered body accounts for 30% to 80% of the total wall thickness of the splitting tool body, and the thickness of the second sintered body accounts for 20% to 70% of the total wall thickness of the splitting tool body.

[0019] If the thickness of the first sintered body accounts for less than 30% of the total wall thickness, that is, the thickness of the second sintered body accounts for more than 70% of the total wall thickness, the first sintered body has limited ability to withstand thermal shock and is prone to cracking, and has no obvious effect on improving wear resistance, and its impact resistance is insufficient, and it is prone to chipping and cracking during use; if the thickness of the first sintered body accounts for more than 80% of the total wall thickness, that is, the thickness of the second sintered body accounts for less than 20% of the total wall thickness, the thickness of the second sintered body is too small, and its contribution to improving the compression and bending resistance of the ceramic splitting cutter is limited, and its ability to withstand thermal shock is limited, and it is prone to cracking, and it is prone to chipping and cracking during use.

[0020] Preferably, the ratio of the total length of the second sintered body to the total length of the cleaver is (10-100):1; more preferably, the ratio of the total length of the second sintered body to the total length of the cleaver is (10-90):1.

[0021] The first sintered body completely wraps around the second sintered body, so that the two bodies are firmly bonded and not easily separated; preferably, when the ratio of the total length of the second sintered body to the total length of the splitting knife is (10-90): 1, the inner hole grinding efficiency is improved, the grinding consumables are reduced, and the defective rates such as inner hole collapse and low roundness can also be reduced.

[0022] Preferably, the ratio of the thickness of the first sintered body to the total length of the splitting cutter is in the range of 40% to 70%.

[0023] At the welding end face, the first sintered body completely surrounds the second sintered body, and the second sintered body is not exposed. Here, the first sintered body has a certain thickness. The first sintered body needs to be exposed at the welding end face, and the second sintered body cannot be exposed. Because the splitter is used at the welding end face, it needs to have sufficient hardness and wear resistance to ensure the service life of the splitter.

[0024] If the thickness of the first sintered body accounts for less than 40%, the first sintered body has limited contribution to improving the overall wear resistance of the splitter. If the proportion is greater than 70%, it is equivalent to the second sintered body accounting for too small a proportion. Due to the high hardness, poor toughness, and high brittleness, it is easy to break during fine processing and actual use, and the molding process is difficult.

[0025] In a second aspect, the present invention further provides a method for preparing a highly wear-resistant and easy-to-process ceramic splitting knife, comprising the following steps:

[0026] (1) uniformly mixing a binder with a first sintered ceramic powder to obtain a first sintered feed; uniformly mixing a binder with a second sintered ceramic powder to obtain a second sintered feed;

[0027] (2) forming the first sintered body feed and the second sintered body feed to obtain a formed body;

[0028] (3) The formed body is sintered to obtain a sintered body, which is then ground to obtain a finished ceramic splitting knife.

[0029] Preferably, the preparation method of the ceramic splitting knife includes injection molding and dry molding.

[0030] More preferably, the specific steps of the injection molding method are as follows:

[0031] (1) Preparation of injection molding feedstock

[0032] a) Preparation of a first sintered body feed: Mixing a binder with a first sintered body ceramic powder to prepare a first sintered body feed; the amount of the binder is 10% to 20wt%, and the amount of the first sintered body ceramic powder is 80% to 90wt%;

[0033] The first sintered ceramic powder is composed of 0.2% to 0.5% Cr 2 O 3 2% to 5% ZrO 2 and 94.5%~97.8% Al 2 O 3 ;

[0034] b) Preparation of a second sintered body feed: Mixing a binder with a second sintered body ceramic powder to prepare a second sintered body feed; the amount of the binder is 10% to 20wt%, and the amount of the second sintered body ceramic powder is 80% to 90wt%;

[0035] The second sintered ceramic powder composition is 2% to 6% Cr 2 O 3 10% to 20% ZrO 2 and 74% to 88% Al2 O 3 ;

[0036] (2) Injection molding

[0037] The first sintered body and the second sintered body in step (1) are fed and injection molded using a double-material injection machine and a double-material injection mold, the second sintered body is first molded, the mold is rotated after cooling, and the first sintered body is molded again, and the molded body is taken out after cooling, the injection temperature of the first sintered body and the second sintered body is 150-200° C., and the cooling time is 6-15s;

[0038] (3) Sintering

[0039] Sintering the splitter formed body obtained in step (2) to obtain a splitter sintered body, the sintering temperature is 1500-1600° C., the holding time is 1-8 hours, and the heating rate is 0.5-10° C. / min;

[0040] (4) Grinding

[0041] The splitting cutter sintered body obtained in step (3) is processed and ground to obtain a ceramic splitting cutter having a structure in which the first sintered body surrounds the second sintered body.

[0042] Preferably, in step (1), the binder is composed of a skeleton material, a lubricant, a dispersant and a plasticizer, wherein the skeleton material includes at least one of PP, PE, HIPS and EVA; the lubricant is paraffin (PW), the dispersant is SA (stearic acid), and the plasticizer includes at least one of DOP, PAEs and DEHP.

[0043] More preferably, the binder composition includes the following components in weight percentage: 30% skeleton material, 55% lubricant, 10% dispersant, and 5% plasticizer.

[0044] Preferably, in step (1), the method for preparing the feed material is mixing, the mixing temperature is 170-190° C., and the mixing time is 4-10 h.

[0045] If the mixing temperature is lower than 170°C, the polymer additives in the binder cannot be dissolved, so the ceramic powder separates from the binder, resulting in uneven mixing and affecting the feeding performance. If the mixing temperature is higher than 190°C, the small molecule additives in the binder decompose, resulting in a reduction in the additive content, affecting the fluidity of the feed and the shrinkage rate during sintering. If the mixing time is too long, the small molecule additives in the binder will decompose, affecting the fluidity of the feed and the shrinkage rate during sintering. If the mixing time is too short, it will lead to uneven mixing and affect the feeding performance.

[0046] In step (2), the injection molding process is used, and the density of each position of the obtained product tends to be consistent, and the performance tends to be consistent. If the injection temperature is too low, the polymer additive cannot be dissolved and is in a highly elastic state. The molecular chain cannot move freely, and the molecular chain breaks, resulting in the separation of the ceramic powder and the binder. The injection pressure will increase, affecting the injection effect. If the temperature is too high, the small molecule additive will decompose, which will affect the injection effect and shrinkage rate. If the cooling time is too short, it will produce sticky film or cause molding defects such as mold release deformation. If the time is too long, the production cycle will be extended, affecting production efficiency.

[0047] In step (3), the sintering temperature is higher than 1600°C. If the sintering temperature is too high, it will cause over-burning problems. The grains of the sintered body will grow excessively, resulting in coarse grains, and the gaps between the grains will become larger, which will reduce the density of the ceramic splitting knife and increase the brittleness, thereby reducing the ceramic splitting knife's ability to resist bending, bending, and processing. The sintering temperature is lower than 1500°C, which is too low, which will cause under-burning problems. If the temperature is insufficient, the grains of the sintered body cannot grow normally, and the grains cannot shrink normally, resulting in the gaps between the grains becoming larger, which will reduce the density of the ceramic splitting knife and increase the brittleness, thereby reducing the ceramic splitting knife's ability to resist bending, bending, and processing. If the holding time is too long, the grains will grow fully, and the grains will gradually grow, eventually leading to problems such as coarse grains. If the grains are coarse, the grains are easy to fall off during the use of the splitting knife, thereby affecting the service life of the splitting knife. If the holding time is too short, the grains do not have enough time to grow, resulting in problems such as under-burning. If the heating time is too fast, the volume shrinks too quickly, which can easily lead to cracking; if the heating time is too slow, the sintering time will be longer, affecting the efficiency.

[0048] More preferably, the specific steps of the dry forming method are as follows:

[0049] (1) Dry pressing feed preparation

[0050] a) Preparation of a first sintered body feed: mixing a binder with a first sintered body ceramic powder to prepare a first sintered body feed; the amount of the binder is 5% to 15wt%, and the amount of the first sintered body ceramic powder is 85-95wt%;

[0051] The first sintered ceramic powder composition is 0.2% to 0.5% Cr 2 O 3 2% to 5% ZrO 2 and 94.5%~97.8% Al 2 O 3 ;

[0052] b) Preparation of a second sintered body feed: Mixing a binder with a second sintered body ceramic powder to prepare a second sintered body feed; the amount of the binder is 5% to 15wt%, and the amount of the second sintered body ceramic powder is 85% to 95wt%;

[0053] The second sintered ceramic powder composition is 2% to 6% Cr 2 O 3 10% to 20% ZrO 2 and 74% to 88% Al 2 O 3 ;

[0054] (2) Dry pressing

[0055] The feed obtained in step (1) is subjected to dry pressing, wherein the second sintered body feed is first placed in a dry pressing mold for pressing, the mold is rotated after pressure relief, and the first sintered body feed is then placed in the mold for pressing to obtain a formed body;

[0056] (3) Sintering

[0057] Sintering the splitter formed body obtained in step (2) to obtain a splitter sintered body, the sintering temperature is 1500-1600° C., the holding time is 1-8 hours, and the heating rate is 0.5-10° C. / min;

[0058] (4) Grinding

[0059] The splitting cutter sintered body obtained in step (3) is processed and ground to obtain the ceramic splitting cutter having a structure in which a first sintered body surrounds a second sintered body.

[0060] In step (1), the adhesive is composed of a water-based adhesive and a lubricant, the water-based adhesive is at least one of PVA, PEG, polyacrylate, and water-based polyurethane, and the lubricant is at least one of 920 and PW.

[0061] More preferably, the composition of the adhesive includes the following components in weight percentage: 10% PVA, 90% 920.

[0062] Preferably, the method for preparing the feedstock is spray granulation, wherein the temperature of the spray granulation is 220-240°C.

[0063] If the spray granulation temperature is lower than 220℃, the polymer additives in the binder cannot be dissolved, so the ceramic powder is separated from the binder, resulting in uneven mixing and affecting the feeding performance. If the spray granulation temperature is higher than 240℃, the small molecule additives in the binder will decompose, resulting in a reduction in the additive content, affecting the fluidity of the feed and the shrinkage rate during sintering.

[0064] In step (2), the dry pressing speed is 8 to 15 strokes / min, the holding time is 0.05 to 1 s, and the pressure relief stroke is 0 to 0.2 mm.

[0065] If the pressing speed is too fast, the pressure drop problem will become more serious, the pressure difference of the molded blank will become larger, and the quality of the molded blank will be affected. If the pressing speed is too slow, it will affect the production efficiency. If the holding time is too short, the pressure drop problem will become more serious, the pressure difference of the molded blank will become larger, and the quality of the molded blank will be affected. If the holding time is too slow, it will affect the production efficiency. If the pressure relief stroke is too long, it will affect the production efficiency.

[0066] In step (3), the sintering temperature is higher than 1600°C. If the sintering temperature is too high, it will cause over-burning problems. The grains of the sintered body will grow excessively, resulting in coarse grains, and the gaps between the grains will become larger, which will reduce the density of the ceramic splitting knife and increase the brittleness, thereby reducing the ceramic splitting knife's ability to resist bending, bending, and processing. The sintering temperature is lower than 1500°C, which is too low, which will cause under-burning problems. If the temperature is insufficient, the grains of the sintered body cannot grow normally, and the grains cannot shrink normally, resulting in the gaps between the grains becoming larger, which will reduce the density of the ceramic splitting knife and increase the brittleness, thereby reducing the ceramic splitting knife's ability to resist bending, bending, and processing. If the holding time is too long, the grains will grow fully, and the grains will gradually grow, eventually leading to problems such as coarse grains. If the grains are coarse, the grains are easy to fall off during the use of the splitting knife, thereby affecting the service life of the splitting knife. If the holding time is too short, the grains do not have enough time to grow, resulting in problems such as under-burning. If the heating time is too fast, the volume shrinks too quickly, which can easily lead to cracking; if the heating time is too slow, the sintering time will be longer, affecting the efficiency.

[0067] At the same time, the main powder Al used in the first sintered body and the second sintered body 2 O 3 The powders are consistent and account for ≥60%. The sintering heating rate is within a reasonable range and its shrinkage trend is basically consistent, so there will be no cracking problem.

[0068] This method can obtain a ceramic chopper with a first sintered body having high hardness and high wear resistance and a second sintered body having high toughness and easy processing, thereby greatly improving the service life of the ceramic chopper and reducing production costs.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] The preparation method of the present invention prepares a ceramic splitting knife, and can obtain a ceramic splitting knife whose first sintered body has high hardness and high wear resistance and whose second sintered body has high toughness and is easy to process, thereby greatly improving the service life of the ceramic splitting knife and reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a structural schematic diagram of the ceramic splitting knife of the present invention. DETAILED DESCRIPTION

[0072] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the protection scope and implementation methods of the present invention are not limited thereto.

[0073] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0074] The compositions of the first sintered ceramic powder and the second sintered ceramic powder are shown in Table 1:

[0075] Table 1

[0076] serial number Sintered body <![CDATA[Cr 2 O 3 / wt%]]> <![CDATA[ZrO 2 / wt%]]> <![CDATA[Al 2 O 3 / wt%]]> R1 First sintered body 0.3 4 95.7 R2 First sintered body 0.5 2.5 97 R3 First sintered body 0.2 2 97.8 R4 Second sintered body 5 15 80 R5 Second sintered body 6 20 74 R6 Second sintered body 2 10 88 DR1 First sintered body 0.1 0.9 99 DR2 First sintered body 1 8 91 DR3 Second sintered body 1 5 94 DR4 Second sintered body 8 30 62 DR5 / 1.5 10 88.5

[0077] The structural design of the ceramic splitter is shown in Table 2:

[0078] Table 2

[0079]

[0080]

[0081] Example 1

[0082] A highly wear-resistant and easy-to-process ceramic splitter, such as Figure 1 As shown, the ceramic splitting knife includes a splitting knife body, a welding nozzle and a wire through hole, wherein the wire through hole extends along the longitudinal axis direction of the splitting knife body to the inner chamfer of the welding nozzle; the splitting knife body is composed of a first sintered body and a second sintered body, wherein the first sintered body surrounds the second sintered body. The structural relationship between the first sintered body and the second sintered body is shown in Table 2.

[0083] A method for preparing a highly wear-resistant and easy-to-process ceramic splitter adopts an injection molding method, and the specific steps are as follows:

[0084] (1) Preparation of injection molding feedstock

[0085] a) Preparation of the first sintered body feedstock: 15 wt% of a binder and 85 wt% of a first sintered body ceramic powder were kneaded at 180° C. for 8 h in a mixer to prepare a feedstock, and the composition of the ceramic powder is shown in Table 1. The binder comprises the following components in weight percentage: PP 30%, PW 55%, SA 10%, and DOP 5%.

[0086] b) Preparation of the second sintered body feedstock: 18 wt% of the binder and 82 wt% of the second sintered body ceramic powder were kneaded at 180° C. for 8 h in a mixer to prepare the feedstock, and the composition of the ceramic powder is shown in Table 1. The binder comprises the following components in weight percentage: PP 30%, PW 55%, SA 10%, and DOP 5%.

[0087] (2) Injection molding

[0088] The first sintered body and the second sintered body in step (1) are fed and injection molded using a double-material injection machine and a double-material injection mold. The second sintered body is first molded. After cooling, the mold is rotated to mold the first sintered body. After cooling, the molded body is taken out. The injection temperature is 180° C. and the cooling time is 6 s.

[0089] (3) Sintering

[0090] The splitter formed body obtained in step (2) is sintered at a sintering temperature of 1570° C., a holding time of 4 h, and a heating rate of 4° C. / min to obtain a splitter sintered body;

[0091] (4) Grinding

[0092] The splitting cutter sintered body obtained in step (3) is processed and ground to obtain a ceramic splitting cutter having a structure in which the first sintered body surrounds the second sintered body.

[0093] Example 2-3

[0094] The difference from Example 1 is that the composition of the first sintered body ceramic powder and the composition of the second sintered body ceramic powder used are different from those in Example 1.

[0095] Embodiment 4-5

[0096] The difference from Example 1 is that the mixing process conditions are different from those in Example 1.

[0097] Embodiment 6-7

[0098] The difference from Example 1 is that the injection molding process conditions are different from those of Example 1.

[0099] Embodiment 8-9

[0100] The difference from Example 1 is that the sintering process conditions are different from those of Example 1.

[0101] Examples 10-13

[0102] The difference from Example 1 is that the structural design of the ceramic splitting knife used is different from that of Example 1.

[0103] The material composition and preparation process parameters of the ceramic splitting knives in Examples 1-13 are shown in Table 3:

[0104] Table 3

[0105]

[0106]

[0107] Comparative Example 1-2

[0108] The difference from Example 1 is that the composition of the first sintered body ceramic powder and the composition of the second sintered body ceramic powder used are different from those in Example 1.

[0109] Comparative Examples 3-4

[0110] The difference from Example 1 is that the mixing process conditions are different from those of Example 1.

[0111] Comparative Examples 5-6

[0112] The difference from Example 1 is that the injection molding process conditions are different from those of Example 1.

[0113] Comparative Examples 7-8

[0114] The difference from Example 1 is that the sintering process conditions are different from those of Example 1.

[0115] Comparative Examples 9-12

[0116] The difference from Example 1 is that the structural design of the ceramic splitting knife used is different from that of Example 1.

[0117] Comparative Example 13

[0118] A ceramic splitting tool comprises a splitting tool body, a welding nozzle and a wire passing through hole, wherein the wire passing through hole extends along the longitudinal axis direction of the splitting tool body to the inner chamfer of the welding nozzle.

[0119] The preparation method of the ceramic splitter is as follows:

[0120] (1) Preparation of feed:

[0121] 15wt% of the binder and 85wt% of the ceramic powder were kneaded at 180°C for 8h in a mixer to prepare a feed material, and the composition of the ceramic powder is shown in Table 1. The binder comprises the following components in weight percentage: PP 30%, PW 55%, SA 10%, and DOP 5%.

[0122] (2) Molding process: The feed material obtained in step (1) is subjected to injection molding at an injection temperature of 180° C. and a cooling time of 6 s.

[0123] (3) Sintering process: The molded body obtained in step (2) is sintered at a sintering temperature of 1570° C., a holding time of 4 h, and a heating rate of 4° C. / min.

[0124] (4) Grinding process: The sintered body obtained in step (3) is processed and ground to obtain the finished splitter.

[0125] The material composition and preparation process parameters of the ceramic splitting knives in Comparative Examples 1-13 are shown in Table 4:

[0126] Table 4

[0127]

[0128]

[0129] Embodiment 14

[0130] A highly wear-resistant and easy-to-process ceramic splitter, such as Figure 1 As shown, the ceramic splitting knife includes a splitting knife body, a welding nozzle and a wire through hole, wherein the wire through hole extends along the longitudinal axis direction of the splitting knife body to the inner chamfer of the welding nozzle; the splitting knife body is composed of a first sintered body and a second sintered body, wherein the first sintered body surrounds the second sintered body. The structural relationship between the first sintered body and the second sintered body is shown in Table 2.

[0131] A method for preparing a highly wear-resistant and easy-to-process ceramic splitter adopts a dry forming method, and the specific steps are as follows:

[0132] (1) Dry pressing feed preparation

[0133] a) Preparation of the first sintered body feed: 8 wt% of a binder and 92 wt% of a ceramic powder were spray granulated at 230° C. using a spray granulator to form a spherical dry-pressed powder. The composition of the ceramic powder is shown in Table 1. The binder comprises the following components in weight percentage: PP 30%, PW 55%, SA 10%, and DOP 5%.

[0134] b) Preparation of the second sintered body feed: 15 wt% of a binder and 85 wt% of a ceramic powder were spray granulated at 230° C. using a spray granulator to form a spherical dry-pressed powder. The composition of the ceramic powder is shown in Table 1. The binder comprises the following components in weight percentage: PP 30%, PW 55%, SA 10%, and DOP 5%.

[0135] (2) Dry pressing

[0136] The feed obtained in step (1) is dry pressed, and the second sintered body feed is first placed in the dry pressing mold for pressing. After the pressure is released, the mold is rotated, and the first sintered body feed is placed again for pressing to obtain a formed body; the pressing speed is 8 strokes / min, the holding time is 0.2s, and the pressure release stroke is 0.1mm.

[0137] (3) Sintering

[0138] Sintering the splitter formed body obtained in step (2) at a sintering temperature of 1570° C., a holding time of 4 h, and a heating rate of 4° C. / min to obtain a splitter sintered body;

[0139] (4) Grinding

[0140] The splitting cutter sintered body obtained in step (3) is processed and ground into a finished product, a steel wire is passed through the inner hole, and grinding liquid is added for processing to obtain the ceramic splitting cutter having a structure in which the first sintered body surrounds the second sintered body.

[0141] Examples 15-16

[0142] The difference from Example 14 is that the composition of the first sintered ceramic powder and the composition of the second sintered ceramic powder used are different from those of Example 14.

[0143] Examples 17-18

[0144] The difference from Example 14 is that the mixing process conditions are different from Example 14.

[0145] Examples 19-20

[0146] The difference from Example 14 is that the injection molding process conditions are different from those of Example 14.

[0147] Examples 21-22

[0148] The difference from Example 14 is that the sintering process conditions are different from those of Example 14.

[0149] Examples 23-26

[0150] The difference from Example 14 is that the structural design of the ceramic splitting knife used is different from that of Example 14.

[0151] The material composition and preparation process parameters of the ceramic splitters 14-26 in Examples are shown in Table 5:

[0152] Table 5

[0153]

[0154]

[0155] Comparative Examples 14-15

[0156] The difference from Example 14 is that the composition of the first sintered ceramic powder and the composition of the second sintered ceramic powder used are different from those of Example 14.

[0157] Comparative Examples 16-17

[0158] The difference from Example 14 is that the mixing process conditions are different from those of Example 14.

[0159] Comparative Examples 18-19

[0160] The difference from Example 14 is that the injection molding process conditions are different from those of Example 14.

[0161] Comparative Examples 20-21

[0162] The difference from Example 14 is that the sintering process conditions are different from those of Example 14.

[0163] Comparative Examples 22-25

[0164] The difference from Example 14 is that the structural design of the ceramic splitting knife used is different from that of Example 14.

[0165] Comparative Example 26

[0166] A ceramic splitting tool comprises a splitting tool body, a welding nozzle and a wire passing through hole, wherein the wire passing through hole extends along the longitudinal axis direction of the splitting tool body to the inner chamfer of the welding nozzle.

[0167] The preparation method of the ceramic splitter is as follows:

[0168] (1) Preparation of feed:

[0169] 8 wt% of the binder and 92 wt% of the ceramic powder were spray granulated at 230° C. using a spray granulator to prepare spherical dry-pressed powder. The composition of the ceramic powder is shown in Table 1. The binder comprises the following components in weight percentage: PP 30%, PW 55%, SA 10%, and DOP 5%.

[0170] (2) Molding process: The feed material obtained in step (1) is dry pressed at a pressing speed of 8 strokes / min, a holding time of 0.2 s, and a pressure relief stroke of 0.1 mm.

[0171] (3) Sintering process: The molded body obtained in step (2) is sintered at a sintering temperature of 1570° C., a holding time of 4 h, and a heating rate of 4° C. / min.

[0172] (4) Grinding process: The sintered body obtained in step (3) is processed and ground into a finished product, a steel wire is passed through the inner hole, and grinding liquid is added for processing.

[0173] The material composition and preparation process parameters of the ceramic splitters in Comparative Examples 14-26 are shown in Table 6:

[0174] Table 6

[0175]

[0176]

[0177] Performance Testing

[0178] 1. The strength and hardness data of the ceramic splitters in Examples 1 to 26 and Comparative Examples 1 to 26 were tested respectively. The specific test methods and compliance requirements are shown in Table 7, and the specific test results are shown in Table 8.

[0179] Table 7 Performance test methods and compliance requirements

[0180]

[0181] Table 8

[0182]

[0183] According to Examples 4-9 and Comparative Examples 3-8 in Table 8, when the ceramic splitting knife is prepared by the injection molding method, by controlling parameters such as mixing temperature, mixing time, injection temperature, cooling time, sintering temperature, holding time and heating rate within the range defined by the present invention, the ceramic splitting knife has excellent strength, hardness and service life.

[0184] According to Examples 17-22 and Comparative Examples 16-21 in Table 8, when the ceramic splitting knife is prepared by the dry forming method, by controlling the parameters such as the dry pressing speed, holding time, pressure relief stroke, sintering temperature, holding time and heating rate within the range defined by the present invention, the ceramic splitting knife has excellent strength, hardness and service life.

[0185] According to Examples 1-3, Examples 14-16, Comparative Examples 1-2, and Comparative Examples 14-15 in Table 8, by controlling the composition of the first sintered ceramic powder and the second sintered ceramic powder within the range defined by the present invention, it is beneficial to improve the strength, hardness and service life of the ceramic splitting knife.

[0186] According to Examples 10-13, Examples 23-26, Comparative Examples 9-13, and Comparative Examples 22-26 in Table 8, the present invention is beneficial to improving the strength, hardness, and service life of the ceramic splitting knife by designing the structure of the first sintered body and the second sintered body.

[0187] 2. The inner hole grinding process data of the splitting cutter of the present invention and the existing single sintered body splitting cutter were compared, as shown in the following Table 9.

[0188] Table 9 Cutter inner hole grinding data

[0189]

[0190] From the comparison of the results of Example 3 and Comparative Example 13, and Example 6 and Comparative Example 26 in Table 9, it can be seen that the ceramic splitting tool of the present invention uses a first sintered body to surround a second sintered body, wherein the second sintered body is a portion with high toughness. When the inner hole of the splitting tool is ground, the grinding time is significantly shortened, the life of the consumables used for inner hole grinding is longer, and the inner hole grinding pass rate is significantly improved.

[0191] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A highly wear-resistant and easy-to-process ceramic splitter, characterized in that: The ceramic splitting knife comprises a splitting knife body, a welding nozzle and a wire through hole, wherein the wire through hole extends along the longitudinal axis direction of the splitting knife body to the inner chamfer of the welding nozzle; the splitting knife body is composed of a first sintered body and a second sintered body, wherein the first sintered body surrounds the second sintered body; The material of the ceramic splitting tool is composed of Cr2O3, ZrO2 and Al2O3, wherein the content of Al2O3 in the material composition of the first sintered body is greater than the content of Al2O3 in the material composition of the second sintered body.

2. The highly wear-resistant and easy-to-process ceramic splitting knife according to claim 1, characterized in that: The material composition of the first sintered body includes the following components: by weight percentage, 0.2% to 0.5% of Cr2O3, 2% to 5% of ZrO2, and 94.5% to 97.8% of Al2O3; The material composition of the second sintered body includes the following components: by weight percentage, 2% to 6% of Cr2O3, 10% to 20% of ZrO2, and 74% to 88% of Al2O3.

3. The highly wear-resistant and easy-to-process ceramic splitting knife according to claim 1, characterized in that: The thickness of the first sintered body accounts for 30% to 80% of the total wall thickness of the splitting tool body, and the thickness of the second sintered body accounts for 20% to 70% of the total wall thickness of the splitting tool body.

4. The highly wear-resistant and easy-to-process ceramic splitting knife according to claim 1, characterized in that: The ratio of the total length of the second sintered body to the total length of the splitting knife is (10-100):

1.

5. The highly wear-resistant and easy-to-process ceramic splitting knife according to claim 1, characterized in that: The ratio of the thickness of the first sintered body to the total length of the splitting cutter is in the range of 40% to 70%.

6. The method for preparing the highly wear-resistant and easy-to-process ceramic splitting knife according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) uniformly mixing a binder and a first sintered ceramic powder to obtain a first sintered feed; uniformly mixing the binder and the second sintered body ceramic powder to obtain a second sintered body feed; (2) forming the first sintered body feed and the second sintered body feed to obtain a formed body; (3) Sintering the molded body to obtain a sintered body, and then grinding it to obtain a finished ceramic splitting knife; the preparation method of the ceramic splitting knife includes injection molding and dry molding.

7. The method for preparing the highly wear-resistant and easy-to-process ceramic splitting knife according to claim 6, characterized in that: The specific steps of the injection molding method are as follows: (1) Preparation of injection molding feedstock The binder is mixed evenly with the first sintered body ceramic powder and the second sintered body ceramic powder respectively to prepare the first sintered body feed and the second sintered body feed; (2) Injection molding The first sintered body and the second sintered body in step (1) are fed and injection molded using a double-material injection machine and a double-material injection mold, the second sintered body is first molded, the mold is rotated after cooling, and the first sintered body is molded again, and the molded body is taken out after cooling, the injection temperature of the first sintered body and the second sintered body is 150-200° C., and the cooling time is 6-15s; (3) Sintering Sintering the splitter formed body obtained in step (2) to obtain a splitter sintered body, the sintering temperature is 1500-1600° C., the holding time is 1-8 hours, and the heating rate is 0.5-10° C. / min; (4) Grinding The splitting cutter sintered body obtained in step (3) is processed and ground to obtain the ceramic splitting cutter.

8. The method for preparing the highly wear-resistant and easy-to-process ceramic splitting knife according to claim 7, characterized in that: In step (1), at least one of (a) to (b) is included: (a) The binder is composed of a skeleton material, a lubricant, a dispersant and a plasticizer; (b) The method for preparing the feed material is mixing, the mixing temperature is 170-190°C, and the mixing time is 4-10 hours.

9. The method for preparing the highly wear-resistant and easy-to-process ceramic splitting knife according to claim 6, characterized in that: The specific steps of the dry forming method are as follows: (1) Dry pressing feed preparation The binder is mixed evenly with the first sintered body ceramic powder and the second sintered body ceramic powder respectively to prepare the first sintered body feed and the second sintered body feed; (2) Dry pressing The feed obtained in step (1) is subjected to dry pressing, wherein the second sintered body feed is first placed in a dry pressing mold for pressing, the mold is rotated after pressure relief, and the first sintered body feed is then placed in the mold for pressing to obtain a formed body; (3) Sintering Sintering the splitter formed body obtained in step (2) to obtain a splitter sintered body, the sintering temperature is 1500-1600° C., the holding time is 1-8 hours, and the heating rate is 0.5-10° C. / min; (4) Grinding The splitting cutter sintered body obtained in step (3) is processed and ground to obtain the ceramic splitting cutter.

10. The method for preparing the highly wear-resistant and easy-to-process ceramic splitting knife according to claim 9, characterized in that: At least one of (a) to (c): (a) In step (1), the adhesive comprises a water-based adhesive and a lubricant; (b) The method for preparing the feed is spray granulation, and the temperature of the spray granulation is 220-240° C.; (c) In step (2), the dry pressing speed is 8 to 15 strokes / min, the holding time is 0.05 to 1 s, and the pressure relief stroke is 0 to 0.2 mm.

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