阅读说明：本技术 一种钛合金正畸钳及其制备方法 (Titanium alloy orthodontic pliers and preparation method thereof ) 是由 张怀龙 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种钛合金正畸钳及其制备方法,钛合金正畸钳的钛合金材质包含且各元素重量百分比为钛(余量)、铝(1-8％)、钒(4-12％)、钼(1-8％)、锆(1-8％)、铌(1-8％)、镍(2-4％)、铬(1-8％)。本发明的目的在于提供一种重量轻、握持感好,耐蚀性好,强度高,且钳口寿命长的钛合金正畸钳及其制备方法。选用钛合金材质,通过金属粉末注射成形直接制备出最终形状的钳体,采用机加工结合EDM后加工方法加工出可实现特定功能的钳口,并采用适当的氮化处理工艺,提高钳口硬度。此制备方法可大幅减少原材料的消耗和加工成本,生产效率高,外观质量优异,经济可行性强,附加值高。最终制品材料相对密度大于97％,钳口硬度高于700HV1,钳口使用寿命高于50000次,使用性能大幅领先同类市场产品。(The invention discloses titanium alloy orthodontic pliers and a preparation method thereof, wherein a titanium alloy material of the titanium alloy orthodontic pliers comprises the following elements of titanium (the balance), aluminum (1-8%), vanadium (4-12%), molybdenum (1-8%), zirconium (1-8%), niobium (1-8%), nickel (2-4%) and chromium (1-8%) in percentage by weight. The invention aims to provide titanium alloy orthodontic pliers with light weight, good holding feeling, good corrosion resistance, high strength and long jaw life and a preparation method thereof. Titanium alloy material is selected, the pliers body with the final shape is directly prepared through metal powder injection molding, the pliers mouth capable of realizing the specific function is machined through a machining and EDM combined post-machining method, and the hardness of the pliers mouth is improved through a proper nitriding treatment process. The preparation method can greatly reduce the consumption of raw materials and the processing cost, and has the advantages of high production efficiency, excellent appearance quality, strong economic feasibility and high added value. The relative density of the final product material is more than 97%, the hardness of the jaw is higher than 700HV1, the service life of the jaw is higher than 50000 times, and the service performance of the jaw is greatly ahead of similar market products.)

1. A titanium alloy orthodontic pliers, comprising: selecting a titanium alloy material; selecting metal for injection molding, mixing powder, mixing, injection molding, degreasing and sintering to obtain the orthodontic pliers blank with the required shape; processing the orthodontic pliers blank by adopting a linear cutting and NC numerical control processing method to process a jaw with a specific use function; the jaws are hardened by adopting a laser nitriding process, the cutting edges are ground flatly, and finally the orthodontic pliers which are light in weight, good in corrosion resistance, excellent in appearance, capable of reaching the jaw hardness of more than 700HV1 and long in service life of more than 50000 times are manufactured.

2. A titanium alloy orthodontic pliers according to claim 1 wherein the titanium alloy material contains and the weight percentages of each element are titanium (balance), aluminum (1-8%), vanadium (4-12%), molybdenum (1-8%), zirconium (1-8%), niobium (1-8%), nickel (2-4%), and chromium (1-8%).

3. The preparation method of the titanium alloy orthodontic pliers is characterized by comprising the following steps: mixing powder, mixing materials, injection molding, degreasing and sintering, surface processing, linear cutting, NC numerical control processing, jaw laser nitriding and blade flat grinding.

4. The method for preparing the titanium alloy orthodontic pliers as claimed in claim 3, wherein the raw materials are two titanium alloys with different morphologies and particle size distributions and the powder are uniformly mixed according to a certain proportion; one of the spherical master alloy titanium alloy powder is-200 to-600 meshes, and the other is-200 to-600 meshes of hydrogenated dehydrogenated titanium powder, wherein the mixing ratio of the two is 1: 1-1: 4.

5. the method for preparing the titanium alloy orthodontic pliers as claimed in claim 3, wherein the sintering temperature is 1300-1400 ℃; the heat preservation time is 120-; the sintering atmosphere is vacuum atmosphere, and the vacuum degree is ensured to be below 10-2 Pa.

6. The method for preparing titanium alloy orthodontic pliers as claimed in claim 3, wherein after the processing and shaping, the jaws are subjected to laser nitriding treatment, the nitriding layer of the laser nitriding of the jaws mainly comprises titanium nitride, the thickness of the nitriding layer is 10-1000 μm, and the hardness of the nitriding layer is more than 700 HV.

Technical Field

The invention relates to the field of powder metallurgy metal injection molding, in particular to titanium alloy orthodontic pliers and a preparation method thereof.

Background

Orthodontic pliers are instruments used for orthodontic operation of teeth, have various effects, and are mainly used for cutting off orthodontic arch wires or clamping and pulling orthodontic arch wires. The orthodontic pliers generally comprise two parts, namely a pliers body and a pliers beak, wherein the pliers body is designed according to a lever principle and is held by hands during operation; the cutting edge is arranged at the position of the forceps beak and is used for cutting off or clamping the orthodontic arch wire. At present, the main material used for preparing the orthodontic pliers body is martensitic stainless steel, the martensitic stainless steel has high strength and high hardness, can bear larger holding force to operate the orthodontic arch wire, but the corrosion resistance of the martensitic stainless steel is limited by carbon content and metallographic structure, and is easy to corrode in the high-temperature steam disinfection process. The jaws are usually connected with hard alloy or high-hardness martensitic stainless steel by adopting a welding or laser cladding method. The hard alloy jaw has high hardness, but has poor welding performance and is easy to fall off; poor corrosion resistance and easy blackening; poor toughness and easy disintegration. The martensite stainless steel is clad by laser, the jaw material is consistent with the clamp body material, the corrosion resistance is poor, the service life of the jaw is short, the jaw is easy to corrode in the using process, and the cutting edge at the position of the beak of the clamp can be shortened rapidly after corrosion, so that the use is influenced.

CN201911149573.X adopts a method of adding a PVD coating to perform surface improvement treatment on the cutting edge of the tong beak, but cannot fundamentally solve the problems that the material of the tong beak substrate is poor in corrosion resistance and the PVD coating is easy to fall off under stress when in use. The orthodontic pliers have good corrosion resistance and long service life of the beak.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides titanium alloy orthodontic pliers and a preparation method thereof.

In order to solve the technical problems, the invention provides the following technical scheme:

the invention provides titanium alloy orthodontic pliers, which comprise the following elements of titanium (balance), aluminum (1-8%), vanadium (4-12%), molybdenum (1-8%), zirconium (1-8%), niobium (1-8%), nickel (2-4%) and chromium (1-8%) in percentage by weight;

another object of the present invention and the technical problem to be solved are also achieved by the following technical solutions. The invention provides a preparation method of titanium alloy orthodontic pliers, which comprises the following steps:

a. the raw materials are two titanium alloys and powder with different shapes and particle size distributions which are uniformly mixed according to a certain proportion; one of the titanium alloy powder is-200-mesh spherical master alloy titanium alloy powder, and the other is-400-mesh hydrogenated and dehydrogenated titanium powder, wherein the mixing ratio of the titanium alloy powder to the hydrogenated and dehydrogenated titanium powder is 1: 1-1: 4;

b. uniformly mixing the alloy powder, adding a certain proportion of a binder, and mixing at the temperature of 120-180 ℃ to prepare a feed material, wherein the mass proportion of the binder is 4-8%;

c. filling the feed into the orthodontic pliers mold cavity with the required shape by an injection molding machine under the conditions of certain temperature and pressure to form an injection green body;

d. and under certain temperature and atmosphere conditions, removing the binder by adopting a heating decomposition method, continuously heating to 1300-1400 ℃, and keeping the temperature for 120-240min for densification to obtain the orthodontic pliers blank with the required shape. The sintering atmosphere is vacuum atmosphere, and the vacuum degree is ensured to be below 10-2 Pa.

e. The appearance of the clamp body is processed by means of grinding and polishing, and then jaws with required functions are formed on the sintered orthodontic clamp blank by means of NC combined with machining means such as EDM and the like;

f. and performing laser nitriding treatment on the jaw to obtain a high-hardness nitrided layer with a certain depth so as to meet the use requirements of strength, hardness and the like.

In a preferred embodiment of the present invention, the organic binder in step b is selected from several of PEG, PW, carnauba wax, polyethylene, polypropylene, EVA, PMMA, SA and other high molecular organic compounds or polymers.

Compared with the prior art, the invention has the following beneficial effects:

1. the whole orthodontic pliers are made of titanium alloy materials, so that the material density is low, the weight is greatly reduced, and the gripping feeling is good;

2. by adopting the metal injection molding process, the utilization rate of raw materials is high, the dimensional precision of products is high, the subsequent machining and EDM discharge machining amount is small, and the production efficiency can be greatly improved;

3. the raw material is formed by mixing spherical master alloy titanium alloy powder and hydrogenated and dehydrogenated pure titanium powder, so that the material cost can be greatly reduced, and the flowability and the shape retention of the prepared feed are ensured;

4. the jaw hardness treated by the laser nitriding process is not lower than 1400HV1, and the titanium alloy matrix material provides excellent corrosion resistance and can ensure the service life of not less than 50000 times.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of an orthodontic pliers blank of the present invention;

fig. 2 is a schematic view of an orthodontic pliers of the invention;

FIG. 3 is a schematic view of orthodontic jaws of the present invention

Fig. 4 is an enlarged view of an orthodontic jaw of the present invention (laser nitrided layer in phantom).

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

Example 1

The titanium alloy orthodontic pliers comprise the following components in parts by weight: titanium (balance), aluminum (3%), vanadium (8%), molybdenum (4%), zirconium (4%), niobium (1%), nickel (2%), chromium (6%). Selecting gas atomized spherical titanium alloy master alloy powder of-200 meshes, wherein the components of the gas atomized spherical titanium alloy master alloy powder are titanium (the balance), aluminum (9%), vanadium (24%), molybdenum (12%), zirconium (12%), niobium (3%), nickel (6%) and chromium (18%); hydrogenated dehydrogenated pure titanium powder of-400 mesh is selected; the two are uniformly mixed by a double-cone mixer according to the weight ratio of 1: 2; mixing the prepared powder with a binder to prepare a feed, wherein the binder comprises 32 wt% of paraffin, 8 wt% of palm wax, 15 wt% of polyethylene wax, 22 wt% of polyethylene, 15 wt% of polypropylene, 6 wt% of EVA, 2 wt% of stearic acid, and the weight ratio of the powder to the binder is 92.1%: 7.9 percent. And (3) forming the feed at 160 ℃ by adopting an injection molding machine and a mold with a designed orthodontic pliers blank, and sintering the formed feed in a sintering furnace at 1300 ℃ for 180min under the vacuum atmosphere condition of less than 10-2Pa to obtain the orthodontic pliers blank. The sintered orthodontic pliers blank is subjected to surface polishing, so that the requirements of appearance and holding hand feeling are met. And then, the mouth part of the clamp blank is processed by adopting linear cutting and numerical control processing to process a jaw structure with the required function. An IPG high-power fiber laser is adopted, laser nitridation treatment is carried out on the jaw area under the condition that the purity of nitrogen is 99.999%, the selected power is 1.4kw, the laser wavelength is 1064nm, the thickness of the obtained nitrided layer is 530um, and the jaw hardness is 1300 HV.

Example two

The selected titanium alloy material comprises the following components: titanium (balance), aluminum (5%), vanadium (5%), molybdenum (5%), niobium (2%), nickel (1%), chromium (3%). Selecting gas atomized spherical titanium alloy master alloy powder of-200 meshes, wherein the components of the gas atomized spherical titanium alloy master alloy powder are titanium (the balance), aluminum (15%), vanadium (15%), molybdenum (15%), niobium (6%), nickel (3%) and chromium (9%); hydrogenated dehydrogenated pure titanium powder of-400 mesh is selected; the two are uniformly mixed by a double-cone mixer according to the weight ratio of 1: 2; mixing the prepared powder with a binder to prepare a feed, wherein the binder comprises 40% of paraffin wax, 10% of palm wax, 5% of polyethylene wax, 10% of polyethylene, 25% of polypropylene, 8% of EVA, 2% of stearic acid, and the weight ratio of the powder to the binder is 92.3%: 7.7 percent. And (3) forming the feed at 160 ℃ by adopting an injection molding machine and a mold with a designed orthodontic pliers blank, and sintering the formed feed in a sintering furnace at 1350 ℃ under the condition of 10kPa pressure and argon atmosphere for 180min to obtain the orthodontic pliers blank. The sintered orthodontic pliers blank is subjected to surface polishing, so that the requirements of appearance and holding hand feeling are met. And then, the mouth part of the clamp blank is processed by adopting linear cutting and numerical control processing to process a jaw structure with the required function. An IPG high-power fiber laser is adopted, laser nitridation treatment is carried out on the jaw area under the condition that the purity of nitrogen is 99.999%, the selected power is 2.0kw, the laser wavelength is 1064nm, the thickness of the obtained nitrided layer is 870um, and the jaw hardness is 900 HV.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.