阅读说明：本技术 一种镍基宽温域高强度自润滑复合材料及其制备方法 (Nickel-based wide-temperature-range high-strength self-lubricating composite material and preparation method thereof ) 是由 王文珍 高强 赵高攀 王斌 陕钰 易戈文 于 2020-05-15 设计创作，主要内容包括：本发明涉及一种镍基宽温域高强度自润滑复合材料,该复合材料由下述按质量百分比计的组分制得：Al粉末：5~10%,Cr粉末：5~10%,Mo粉末：5~10%,Ta粉末：0~8%,Al<Sub>2</Sub>O<Sub>3</Sub>粉末：0~5%,Ag粉末：0~15%,余量为Ni。本发明还公开了该复合材料的制备方法。本发明具有较高机械性能和良好摩擦学性能,可适用于航空发动机涡轮叶片与外环、叶冠啮合面、涡轮传动机构轴与轴套等对机械性能和摩擦磨损性能要求较高的高温摩擦副。(The invention relates to a nickel-based wide-temperature-range high-strength self-lubricating composite material which is prepared from the following components in percentage by mass: al powder: 5-10%, Cr powder: 5-10%, Mo powder: 5-10%, Ta powder: 0 to 8% of Al 2 O 3 Powder: 0-5%, Ag powder: 0-15% and the balance of Ni. The invention also discloses a preparation method of the composite material. The invention has higher mechanical property and good tribological property, and can be suitable for high-temperature friction pairs with higher requirements on mechanical property and frictional wear property, such as turbine blades of aero-engines, outer rings, blade shroud meshing surfaces, turbine transmission mechanism shafts and shaft sleeves and the like.)

1. The nickel-based wide-temperature-range high-strength self-lubricating composite material is characterized in that: the composite material is prepared from the following components in percentage by mass: al powder: 5-10%, Cr powder: 5-10%, Mo powder: 5-10%, Ta powder: 0 to 8% of Al₂O₃Powder: 0-5%, Ag powder: 0-15% and the balance of Ni.

2. The preparation method of the nickel-based wide-temperature-range high-strength self-lubricating composite material as claimed in claim 1, wherein the preparation method comprises the following steps: firstly weighing according to the proportion, and then mixing Ni, Cr, Mo, Al, Ta, Ag and Al₂O₃Mixing the powder, and performing ball milling to obtain mixed powder; and finally, filling the mixed powder into a graphite mold, placing the graphite mold into a vacuum hot-pressing sintering furnace for hot-pressing sintering, and cooling the graphite mold to room temperature along with the furnace after sintering is finished to obtain the block Ni-based composite material.

3. The preparation method of the nickel-based wide-temperature-range high-strength self-lubricating composite material as claimed in claim 2, wherein the preparation method comprises the following steps: the ball milling conditions are that the ball material mass ratio is 10: 1, the rotating speed is 250r/min or 400r/min, and the ball milling is carried out for 10 to 20 hours under the protection of anhydrous methanol.

4.The preparation method of the nickel-based wide-temperature-range high-strength self-lubricating composite material as claimed in claim 2, wherein the preparation method comprises the following steps: the vacuum hot-pressing sintering condition is that the heating rate is 5-10 ℃/min, the sintering temperature is 1100-1200 ℃, the sintering pressure is 20-30 MPa, the sintering time is 30-120 min, and the vacuum degree is 10^-3~10^-1Pa。

Technical Field

The invention relates to the technical field of material design and preparation, in particular to a nickel-based wide-temperature-range high-strength self-lubricating composite material and a preparation method thereof.

Background

The high-speed development of high-tech industries such as aviation, aerospace, nuclear engineering, energy power and the like puts forward higher and higher requirements on the lubricating performance and strength of materials in service under extreme harsh working conditions (such as ultrahigh/low temperature, ultrahigh load, high speed, special medium and atmosphere), and especially puts forward more urgent requirements on materials with high strength, stability and reliable lubricating performance in a wide temperature range (room temperature to 1000 ℃) by key friction pairs (such as a turbine blade and an outer ring, a blade crown meshing surface, a turbine transmission mechanism shaft and a shaft sleeve and the like) of high-temperature machinery represented by an advanced engine; meanwhile, since the material is required to have a sufficiently high tensile strength, compressive strength, etc. within a wide temperature range due to long-term operation under complicated stress, high-end equipment manufacturing and advanced technical industries have great demands for materials and technologies having high mechanical properties and good tribological properties within a wide temperature range.

Chinese patent CN 109402435A discloses a nickel-aluminum-based wide-temperature-range self-lubricating alloy and a preparation method thereof, when the nickel-aluminum-based wide-temperature-range self-lubricating alloy is matched with WC balls, the friction coefficient is 0.20-0.50 within the range of room temperature-1000 ℃, and the wear rate is 1.2-24 × 10^-5mm³in/Nm. Chinese patent CN 103572137 discloses a NiCr-Al alloy₂O₃Self-lubricating composite material, preparation method thereof and Al₂O₃When the ball is matched, the friction coefficient is 0.274-0.475 at room temperature-1000 ℃, and the wear rate is 0.546-8.31 × 10^-5mm³in/Nm. The above patent does not relate to the mechanical properties of the material. Chinese patent CN105441707A discloses a nickel-based self-lubricating composite material compounded with graphite and lead (Pb), which has good lubricating and wear-resisting properties at room temperature to 500 ℃ and higher room-temperature compressive strength>300 MPa). Chinese patent CN 1360075A discloses a nickel-based self-lubricating alloy containing Fe, Co, Nb, Se and graphite, which has low friction and wear resistance within the temperature range of room temperature to 600 ℃, but has low compressive strength, the room temperature compressive strength is only 6.80-9.86 MPa, and the 600 ℃ compressive strength is 4.34-6.65 MPa. The nickel-based self-lubricating alloy disclosed by Chinese patents CN1073727A, CN1082620A, CN1101681A and the like realizes good tribological performance at room temperature to 700 ℃, but has poor mechanical performance in a wide temperature range. In the published literature reports, only two reports are currently seen to examine simultaneouslyMechanical and tribological properties of materials over a wide temperature range, with L iu et Al reporting NiCr-40wt.% Al₂O₃The material has a compressibility (tribologyInternational 84 (2015) of 1-8) at room temperature to 1000 ℃, but Al thereof₂O₃Up to 40wt.%, forms a cermet with Ni, has poor material processability, and has not been investigated for tensile properties over a wide temperature range. Yanglinlan and the like report tensile, compression and frictional wear properties (Chinese non-ferrous metal report, 27 vol., 11 th, 2267-; the material has poor abrasion resistance below 500 ℃, and the abrasion rate is 10^-3~10^-4mm³Of the order of/Nm. At present, no public report about the composite material with optimized and unified tensile compression performance and frictional wear performance within the range of room temperature to 1000 ℃ is found.

The difficulty in developing a material with optimized and unified mechanical properties and tribological properties in a wide temperature range is that if the tribological properties in the wide temperature range are realized, lubricants with different temperature ranges are required to be compounded or cooperated, and the lubricants have lower melting points and lower hardness (soft metals such as Ag and Au), or have poor compatibility with metal matrixes (graphite, Au, etc.),h-BN、CaF₂、BaF₂And eutectic crystals thereof, etc.), causing severe cracking of the matrix phase, resulting in a decrease in the mechanical properties of the material.

Disclosure of Invention

The invention aims to solve the technical problem of providing a nickel-based wide-temperature-range high-strength self-lubricating composite material with higher mechanical property and good tribological property.

The invention aims to solve another technical problem of providing a preparation method of the nickel-based wide-temperature-range high-strength self-lubricating composite material.

In order to solve the problems, the invention provides a nickel-based wide-temperature-range high-strength self-lubricating composite material, which is characterized in that: the composite material is prepared from the following components in percentage by mass: al powder: 5-10%, Cr powder: 5-10%, Mo powder: 5 to 10%, Ta powder: 0 to 8% of Al₂O₃Powder: 0-5%, Ag powder: 0-15% and the balance of Ni.

The preparation method of the nickel-based wide-temperature-range high-strength self-lubricating composite material is characterized by comprising the following steps of: firstly weighing according to the proportion, and then mixing Ni, Cr, Mo, Al, Ta, Ag and Al₂O₃Mixing the powder, and performing ball milling to obtain mixed powder; and finally, filling the mixed powder into a graphite mold, placing the graphite mold into a vacuum hot-pressing sintering furnace for hot-pressing sintering, and cooling the graphite mold to room temperature along with the furnace after sintering is finished to obtain the block Ni-based composite material.

The ball milling conditions are that the ball material mass ratio is 10: 1, the rotating speed is 250r/min or 400r/min, and the ball milling is carried out for 10 to 20 hours under the protection of anhydrous methanol.

The vacuum hot-pressing sintering condition is that the heating rate is 5-10 ℃/min, the sintering temperature is 1100-1200 ℃, the sintering pressure is 20-30 MPa, the sintering time is 30-120 min, and the vacuum degree is 10^-3~10^-1Pa。

Compared with the prior art, the invention has the following advantages:

1. the invention designs the strength of the material, uses Ni with excellent high-temperature mechanical property as a matrix, and adds alloy strengthening elements such as Al, Cr, Mo, Ta and the like and dispersion strengthening oxide α -Al₂O₃And the alloy is prepared by adopting a powder metallurgy method (ball milling and vacuum hot-pressing sintering), and TaC and Al are generated in situ in the hot-pressing sintering process₂O₃And (3) an equal dispersion strengthening phase. Wherein Al reacts with Ni to form Ni₃The Al (gamma ') phase plays a role in precipitation strengthening, has the characteristics of dissolution at high temperature and re-precipitation at low temperature aging due to large solubility change of the gamma ' phase in a Ni matrix, always precipitates on the matrix, has good strength and can participate in deformation, and cannot generate serious brittleness due to the precipitation of a large amount of gamma ' or the existence of a large gamma ' phase, so that the Al (gamma ') phase is a main strengthening phase in the nickel-based material; cr, Mo, Ta and other elements play a role in solid solution strengthening; the dispersion strengthening phase has high melting point, good thermal stability and chemical stability, does not react with the matrix, is dispersed in the matrix to block dislocation movement, and plays a role inThe strengthening effect can ensure that the material is at a higher temperature (0.85-0.9T)_{Fusion furnace}) Has very high-temperature strength; therefore, the high mechanical performance of the material in a wide temperature range can be realized through a composite strengthening mechanism of solid solution strengthening, precipitation strengthening and dispersion strengthening.

2. In the present invention, elements such as Cr and Mo are advantageous to the tribological properties of the composite material, such as Cr oxide Cr₂O₃Can play a role in strengthening and resisting abrasion; MoO produced by oxidation of Mo at high temperature₃And molybdate generated by the tribochemical reaction has excellent high-temperature lubricity.

3. In the invention, high-temperature lubricant is not added, but NiO and MoO generated in the friction reaction process₃Silver molybdate and the like can be used as a medium-high temperature lubricant and can play a role in lubricating at medium and high temperatures; oxides of Al and Cr, Al₂O₃And Cr₂O₃Etc. may also play a wear-resisting role.

4. The invention can realize the continuous lubrication at room temperature to 1000 ℃ by the cooperation of self-generated lubricating phase of Ag and (or) tribochemical reaction.

5. The invention realizes higher mechanical performance in a wide temperature range by utilizing a composite strengthening mechanism of solid solution strengthening, precipitation strengthening and dispersion strengthening; meanwhile, a low-temperature lubricating phase which does not cause serious fracture to a matrix phase and can generate a new high-temperature lubricating phase in situ through a tribochemical reaction in a high-temperature friction process is selected, and continuous lubrication of the material in a wide temperature range (RT-1000 ℃) is realized through compounding and cooperation of the low-temperature lubricating phase and the high-temperature lubricating phase generated in situ through the tribochemical reaction, so that the high-temperature lubricating phase is suitable for high-temperature friction pairs with high requirements on mechanical properties and frictional wear properties, such as an aeroengine turbine blade, an outer ring, a blade crown meshing surface, a turbine transmission mechanism shaft and a shaft sleeve.

⑴ composition and microstructure of the resulting composite of the invention:

typical microstructures of the resulting composite material of the present invention include: ni-based solid solution matrix phase with Cr, Mo and other elements dissolved therein, and oxide (Al) dispersed therein₂O₃) Or a carbide dispersion strengthened phase (TaC) and a continuously distributed Ag lubricating phase.

⑵ testing the performance of the composite material obtained by the invention:

① tensile Property test

The test method comprises the steps of testing the tensile property of the material by using an Instron 5582 type electronic universal material testing machine, wherein a tensile sample is a plate-shaped test sample, the gauge length is 20mm (length) × 4mm (width) × 2mm (thickness), the tensile test temperature is respectively room temperature, 400 ℃, 800 ℃ and 1000 ℃, the tensile rate is 0.3 mm/min before yielding and 2.3 mm/min after yielding.

② compression performance test:

the test method comprises testing the compression performance of the material by an electronic universal tester, wherein the sample size is phi 6mm × 9mm, the compression test temperature is room temperature, 400 ℃, 800 ℃ and 1000 ℃, and the strain rate is 0.5 mm/min.

③ tribology Performance test

The test method is carried out on a UMT-3 high-temperature friction tester, the disc is the composite material of the invention, the size is phi 24mm × 3mm, and the dual ball is Al with phi 10mm₂O₃Ceramic ball, load 20N, sliding speed 200r/min, rotating radius 5mm, run time 60 minutes. The test temperatures were room temperature, 400 and 800 deg.C (the maximum test temperature could only be up to 800 deg.C due to the limitations of the tribometer itself).

The tensile, compressive and tribological performance test results of the nickel-based composite material obtained by the invention are shown in table 1.

TABLE 1 tensile, compressive and tribological Properties of the Nickel-based composite obtained according to the invention

As shown in Table 1, the high-temperature-resistant high-strength alloy material takes Ni with excellent high-temperature performance as a matrix, Cr, Mo and Al are added to play roles in precipitation strengthening and solid solution strengthening, and refractory metal oxides or carbides are generated in situ in the process of addition or hot-pressing sintering to play a role in dispersion strengthening, so that high tensile and compressive strength of the material at room temperature of 1000 ℃ is ensured; the good tribology performance in a wide temperature range (room temperature-1000 ℃) is realized through the synergistic lubrication effect of Ag and (or) silver molybdate, nickel oxide, molybdenum oxide and the like formed in the tribochemistry reaction process (although the tribology performance is only tested to 800 ℃, the material also has good tribology performance at 1000 ℃ according to the inference of a microstructure).

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a composition and microstructure diagram of a nickel-based wide-temperature-range high-strength self-lubricating composite material prepared in example 1 of the present invention.

Fig. 2 is a composition and microstructure diagram of the nickel-based wide-temperature-range high-strength self-lubricating composite material prepared in example 2 of the present invention.

FIG. 3 is a composition and microstructure diagram of a nickel-based wide-temperature-range high-strength self-lubricating composite material prepared in example 3 of the present invention.

Detailed Description