A (ti,mo)c reinforced nickel-based alloy coating and a method of making the same

Abstract

The application relates to a (Ti, Mo)C reinforced nickel-based alloy coating and a preparation method thereof, and belongs to the technical field of surface strengthening. The (Ti, Mo)C reinforced nickel-based alloy coating is a cermet coating formed by plasma cladding on a base material; the reinforcing body in the cermet coating is a (Ti, Mo)C ceramic phase; the cermet coating is composed of the following chemical elements according to the weight percentage: Ti 16-24wt%, C 4-6wt%, Mo 2-5wt%, Si 2.3-2.7wt%, B 1.2-1.4wt%, and the balance is Ni. The (Ti, Mo)C reinforced nickel-based alloy coating is prepared on the base material based on plasma cladding. The (Ti, Mo)C ceramic phase in the (Ti, Mo)C reinforced nickel-based alloy coating is uniformly distributed in the nickel alloy coating, and the (Ti, Mo)C reinforced nickel-based alloy coating has good hardness and wear resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to a (Ti, Mo)C reinforced nickel-based alloy coating and a preparation method thereof, and belongs to the technical field of surface strengthening. BACKGROUND

[0002] According to statistics, more than 80% of the failure of key industrial components in China is caused by surface wear, corrosion, etc. If directly scrapped, it not only increases the manufacturing cost, but also causes great waste of resources. As a senior form of green circular economy, remanufacturing can realize the rebirth of failed key components by using various surface repair technologies such as plasma, laser, electron beam, etc. Surfacing is one of the commonly used surface repair technologies, but the application range of surfacing is limited due to the limitation of the chemical composition of the electrode, and in the process of surfacing, there is an operation of removing the coating, such as incomplete removal of the coating, which is easy to form inclusions in the surfacing layer, and reduces the mechanical properties of the coating. Plasma cladding is also a common surface repair technology, which has the characteristics of wide material selectivity and unrestricted shape of cladding area. By forming a coating on the surface of the failed component which is metallurgically combined with the substrate, the surface size of the component is restored and the expected wear resistance and long service life of the component are achieved. Plasma cladding has become an important means for efficient repair and remanufacturing of key components of high-end equipment.

[0003] In the prior art, the alloy powder commonly used in plasma cladding is a self-fluxing alloy powder formed by adding Si, B and other elements with strong deoxidizing and self-fluxing effect in a Ni, Fe, Co or other base alloy. However, a single self-fluxing alloy powder cannot meet the wear resistance requirements in high-temperature harsh service environments, so ceramic reinforcing phases are often added, and TiC and WC are the main additional ceramic reinforcing phases. In recent years, with the over-consumption of tungsten resources becoming scarce, the price of tungsten has been rising year by year, which limits the use of tungsten in plasma cladding, which encourages the use of other materials to replace tungsten products. TiC has high hardness, low price and stable structure at high temperature, and its density is only 1 / 3 of that of WC. The use of TiC instead of WC reinforcing phase in alloy coating can reduce the cost. However, due to the low density of TiC, it is easy to float up in the coating formed by plasma cladding, resulting in uneven distribution of TiC in the surface layer and the inner layer of the coating. Although the formed coating has good hardness and wear resistance in the early stage of use, as the use time prolongs, the surface layer of the coating is consumed or damaged, and the remaining alloy coating has less TiC, so the expected service life of the coating is reduced. Once the TiC wear-resistant particles on the surface of the coating are worn off during subsequent machining, the actual proportion of the reinforcing phase in the coating is greatly reduced, which affects the expected service life of the coating. SUMMARY

[0004] In view of the problem that the uneven distribution of TiC reinforcing phase in the coating affects the expected service life of the coating, the application provides a (Ti, Mo)C reinforced nickel-based alloy coating and a preparation method thereof, wherein the reinforcing phase in the (Ti, Mo)C reinforced nickel-based alloy coating is uniformly distributed, and the hardness and the expected service life of the coating are improved.

[0005] The (Ti, Mo)C reinforced nickel-based alloy coating of the application is a cermet coating formed by plasma cladding on a base material; a (Ti, Mo)C ceramic phase is formed in the cermet coating; the cermet coating is composed of the following chemical elements in terms of weight percentage: Ti 16-24 wt%, C 4-6 wt%, Mo 2-5 wt%, Si 2.3-2.7 wt%, B 1.2-1.4 wt%, and the balance of Ni and inevitable impurities.

[0006] In one specific embodiment of the application, the base material is steel.

[0007] In one specific embodiment of the application, the thickness of the cermet coating is 3-5 mm.

[0008] In one specific embodiment of the application, the (Ti, Mo)C ceramic phase is a solid solution phase and has a core-shell structure; the (Ti, Mo)C ceramic phase has a face-centered cubic structure.

[0009] In one specific embodiment of the application, the cermet coating is composed of the following chemical elements: Ti 16 wt%, C 4 wt%, Mo 2 wt%, Si 2.5 wt%, B 1.3 wt%, and the balance of Ni; or Ti 20 wt%, C 5 wt%, Mo 3 wt%, Si 2.4 wt%, B 1.3 wt%, and the balance of Ni; or Ti 24 wt%, C 6 wt%, Mo 4 wt%, Si 2.3 wt%, B 1.2 wt%, and the balance of Ni.

[0010] The preparation method of the (Ti, Mo)C reinforced nickel-based alloy coating of the application comprises the following steps:

[0011] a. Mixing: according to the weight percentage of each chemical element in the nickel-based alloy coating material, pre-mixed powders of TiC, Mo and NiBSi micropowder are weighed and mixed to obtain a mixed powder.

[0012] b. Plasma cladding: the mixed powder is plasma cladded on the surface of the base material to form a cermet coating.

[0013] In one specific embodiment of the application, in step a, the pre-mixed powder is a spherical powder.

[0014] In one specific embodiment of the present application, in the mixing step a, the particle size of the mixed powder is 53-150 μm.

[0015] In one specific embodiment of the present application, in the plasma cladding step b, the plasma cladding is carried out in an inert protective gas; preferably, the inert protective gas is any one or a mixture of any several of helium, neon, argon, krypton and radon.

[0016] In one specific embodiment of the present application, the condition parameters of the plasma cladding are: current 120-170 A; linear velocity 1-4 mm / s; powder feeding amount 20-60 g / min; inert protective gas flow 5-15 L / min; overlap amount 40-60%; spot size 3-6 mm.

[0017] The (Ti, Mo)C reinforced nickel-based alloy coating of the present application forms a (Ti, Mo)C ceramic solid solution phase, has a core-shell cladding phase morphology, has a face-centered cubic structure of unit cell, and the (Ti, Mo)C ceramic phase is uniformly distributed in the nickel alloy coating. The (Ti, Mo)C reinforced nickel-based alloy coating has good hardness and wear resistance. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Figure 1 is a microstructure morphology diagram of the (Ti, Mo)C reinforced nickel-based alloy coating of the present application;

[0019] Figure 2 Figure 2 is a microstructure morphology diagram of the pre-mixed powder of the present application;

[0020] Figure 3 Figure 3 is an X-ray diffraction diagram of the (Ti, Mo)C reinforced nickel-based alloy coating of the present application. DETAILED DESCRIPTION

[0021] The (Ti, Mo)C reinforced nickel-based alloy coating of the present application is a cermet coating formed by plasma cladding on a base material; a (Ti, Mo)C ceramic phase is formed in the cermet coating; the cermet coating is composed of the following chemical elements in percentage by weight: Ti 16-24 wt%, C 4-6 wt%, Mo 2-5 wt%, Si 2.3-2.7 wt%, B 1.2-1.4 wt%, and the balance of Ni.

[0022] Based on the above Figure 1 In the nickel-based alloy, TiC and Mo are introduced to form a (Ti, Mo)C ceramic solid solution phase, and the microstructure of the (Ti, Mo)C ceramic phase is a core-shell cladding phase morphology; based on the above Figure 3The crystal cell of the (Ti, Mo)C ceramic phase in the (Ti, Mo)C reinforced nickel-based alloy coating is a face-centered cubic structure; and the comprehensive results show that the (Ti, Mo)C ceramic phase is uniformly distributed in the coating alloy, so that the coating has stable hardness and wear resistance.

[0023] In one specific embodiment of the present application, the base material is steel; the chemical elements include Fe, C, Cr, etc., and the cermet coating contains trace elements such as Fe and Cr in addition to Ti, C, Mo, Si, B and Ni, which are also brought into the base material steel during the plasma cladding process, so that the content of trace elements in the cermet coating is 0.2-0.5wt%.

[0024] In one specific embodiment of the present application, the thickness of the cermet coating is 3-5mm.

[0025] In one specific embodiment of the present application, the (Ti, Mo)C ceramic solid solution phase is a face-centered cubic structure.

[0026] In one specific embodiment of the present application, the cermet coating is composed of the following chemical elements: Ti 16wt%, C 4wt%, Mo 2wt%, Si 2.5wt%, B 1.3wt%, trace elements 0.3wt% and the balance of Ni;

[0027] or Ti 20wt%, C 5wt%, Mo 3wt%, Si 2.4wt%, B 1.3wt%, trace elements 0.3wt% and the balance of Ni;

[0028] or Ti 24wt%, C 6wt%, Mo 4wt%, Si 2.3wt%, B 1.2wt%, trace elements 0.2wt% and the balance of Ni.

[0029] In one specific embodiment of the present application, the preparation method of the (Ti, Mo)C reinforced nickel-based alloy coating comprises the following steps:

[0030] a. Mixing: according to the weight percentage of each chemical element in the nickel-based alloy coating material, the pre-mixed powder of TiC, Mo and Ni and the micron powder of NiBSi are weighed and mixed to obtain a mixed powder.

[0031] b. Plasma cladding: the mixed powder is plasma cladded on the surface of the base material to form a cermet coating.

[0032] The micron powder of NiBSi is made by gas atomization method; the pre-mixed powder of TiC, Mo and Ni is made by spray granulation method.

[0033] Before forming a metal-ceramic coating on the substrate material surface, the surface of the substrate material is polished to a high gloss, and then plasma cladding is performed to obtain the metal-ceramic coating.

[0034] In one specific embodiment of the present invention, based on the appendix Figure 2 Step a, mixing, wherein the pre-mixed powder is spherical powder.

[0035] In one specific embodiment of the present invention, step a, mixing, involves mixing powder with a particle size of 53-150 μm.

[0036] In one specific embodiment of the present invention, step b, plasma cladding, is carried out in an inert protective gas; preferably, the inert protective gas is any one or a mixture of any of helium, neon, argon, krypton, and radon.

[0037] In one specific embodiment of the present invention, the plasma cladding conditions are as follows: current 120-170A; linear velocity 1-4mm / s; powder feed rate 20-60g / min; inert protective gas flow rate 5-15L / min; overlap rate 40-60%; and spot size 3-6mm.

[0038] In this invention, a (Ti,Mo)C ceramic phase is formed in the nickel alloy matrix in the (Ti,Mo)C reinforced nickel-based alloy coating, and the (Ti,Mo)C ceramic phase is uniformly distributed in the nickel alloy matrix. The hardness and wear resistance of the coating are long-lasting and improve the expected service life of the coating.

[0039] The specific embodiments of the present invention will be further described below with reference to examples, but the present invention is not limited to the scope of the embodiments described herein.

[0040] Example 1

[0041] The (Ti,Mo)C reinforced nickel-based alloy coating is a cermet coating formed by plasma cladding on a substrate material, in which a (Ti,Mo)C ceramic phase is formed. By weight percentage, the cermet coating is composed of the following chemical elements: Ti 16wt%, C 4wt%, Mo 2wt%, Si 2.5wt%, B 1.3wt%, trace elements 1.3wt%, and the balance being Ni.

[0042] The method for preparing (Ti,Mo)C reinforced nickel-based alloy coatings includes the following steps:

[0043] 1) Preparation of NiBSi micron powder based on gas atomization method;

[0044] 2) A pre-mixed powder containing TiC, Mo, and Ni was obtained based on spray granulation.

[0045] 3) The pre-mixed powder of NiBSi micropowder, TiC powder, Mo powder and Ni powder is uniformly mixed to obtain a cermet mixed powder raw material, which is loaded into a powder feeding barrel;

[0046] 4) The surface of the Q235 steel is polished bright, and the parameters of the plasma cladding are adjusted as follows: current 120 A, linear speed 4 mm / s, powder feeding amount 20 g / min, inert protective gas flow 11 L / min, overlap amount 50%, and spot size 5 mm. The (Ti, Mo)C reinforced nickel-based alloy coating is obtained on the surface of the Q235 steel.

[0047] The Rockwell hardness of the (Ti, Mo)C reinforced nickel-based alloy coating in this embodiment is 52 HRC, and the friction coefficient is 0.47.

[0048] Example 2

[0049] The (Ti, Mo)C reinforced nickel-based alloy coating is a cermet coating formed by plasma cladding on a base material, and a (Ti, Mo)C ceramic phase is formed in the cermet coating. The cermet coating is composed of the following chemical elements in terms of weight percentage: Ti 20 wt%, C 5 wt%, Mo 3 wt%, Si 2.4 wt%, B 1.3 wt%, trace elements 1.3 wt%, and the balance of Ni.

[0050] The preparation method of the (Ti, Mo)C reinforced nickel-based alloy coating in this embodiment is the same as that in Example 1.

[0051] The Rockwell hardness of the (Ti, Mo)C reinforced nickel-based alloy coating in this embodiment is 55 HRC, and the friction coefficient is 0.39.

[0052] Example 3

[0053] The (Ti, Mo)C reinforced nickel-based alloy coating is a cermet coating formed by plasma cladding on a base material, and a (Ti, Mo)C ceramic phase is formed in the cermet coating. The cermet coating is composed of the following chemical elements in terms of weight percentage: Ti 24 wt%, C 6 wt%, Mo 4 wt%, Si 2.3 wt%, B 1.2 wt%, trace elements 1.2 wt%, and the balance of Ni.

[0054] The preparation method of this embodiment is the same as that in Example 1.

[0055] The Rockwell hardness of the (Ti, Mo)C reinforced nickel-based alloy coating in this embodiment is 59 HRC, and the friction coefficient is 0.3.

Claims

1. A (Ti,Mo)C reinforced nickel-based alloy coating, characterized in that, The coating is a cermet coating formed by plasma cladding on a base material; the reinforcing body in the cermet coating is a (Ti, Mo)C ceramic phase; the (Ti, Mo)C ceramic phase is a solid solution phase, has a core-shell structure, and is uniformly distributed in the coating; The cermet coating is composed of the following chemical elements in percentage by weight: Ti 16-24 wt%, C 4-6 wt%, Mo 2-5 wt%, Si 2.3-2.7 wt%, B 1.2-1.4 wt%, and the balance of Ni and inevitable impurities.

2. The (Ti,Mo)C reinforced nickel-based alloy coating according to claim 1, characterized in that The base material is steel.

3. The (Ti,Mo)C reinforced nickel-based alloy coating according to claim 1, characterized in that, The thickness of the cermet coating is 3-5 mm.

4. The (Ti,Mo)C reinforced nickel-based alloy coating according to claim 1, characterized in that, The (Ti, Mo)C ceramic phase has a face-centered cubic structure.

5. The (Ti,Mo)C reinforced nickel-based alloy coating according to claim 1, characterized in that, The cermet coating is composed of the following chemical elements: Ti 16 wt%, C 4 wt%, Mo 2 wt%, Si 2.5 wt%, B 1.3 wt%, and the balance of Ni; or Ti 20 wt%, C 5 wt%, Mo 3 wt%, Si 2.4 wt%, B 1.3 wt%, and the balance of Ni; or Ti 24 wt%, C 6 wt%, Mo 4 wt%, Si 2.3 wt%, B 1.2 wt%, and the balance of Ni.

6. The method of producing a (Ti,Mo)C reinforced nickel-based alloy coating according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: a. Mixing: according to the weight percentage of each chemical element in the nickel-based alloy coating material, the pre-mixed powder of TiC, Mo, and NiBSi micropowder is weighed and mixed to obtain a mixed powder; b. Plasma cladding: the mixed powder is plasma cladded on the surface of the base material to form a cermet coating.

7. The preparation method according to claim 6, characterized in that, In step a, the pre-mixed powder is a spherical powder.

8. The preparation method according to claim 6, characterized in that, In step a, the particle size of the mixed powder is 53-150 μm.

9. The preparation method according to claim 6, characterized in that, In step b, the plasma cladding is carried out in an inert protective gas.

10. The method of claim 9, wherein, The inert protective gas is any one or a mixture of any several of helium, neon, argon, krypton, and radon.

11. The preparation method according to claim 6, characterized in that, The condition parameters of the plasma cladding are: current 120-170 A; linear velocity 1-4 mm / s; powder feeding amount 20-60 g / min; inert protective gas flow 5-15 L / min; overlap amount 40-60%; and spot size 3-6 mm.

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