CN103866320B - A kind of method of improving tungsten carbide of nickel-base laser cladding coating - Google Patents
A kind of method of improving tungsten carbide of nickel-base laser cladding coating Download PDFInfo
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Abstract
The present invention proposes a kind of method of improving tungsten carbide of nickel-base laser cladding coating, it is characterized in that, comprise the steps: step 1, in tungsten carbide of nickel-base coated powder, add rare earth lanthanum oxide powder, the mass percent of its component is: lanthana 0.8%, and tungsten carbide 40%, Ni-based is 59.2%, above-mentioned raw materials powder is placed in to airtight container, puts into batch mixer mixing 1-3h; Step 2, laser melting coating, taking common A3 steel as base material, is polished matrix with 400 order sand paper bright and clean, and with acetone soln wiping except surface and oil contaminant; Laser power is 1500-1800w, and selected hot spot is wide is 5-10mm, and sweep speed is 1-2m/min, and protection gas is nitrogen, and throughput is 15l/min, and powder feeding rate is 3-10g/min.
Description
Technical field
The invention belongs to laser melting coating ceramic-metal composite field, be one improve tungsten carbide of nickel-base swashThe technique of light cladding coating and method, relate in particular to a kind of laser metal ceramal powder and preparation side thereofMethod and melting and coating process.
Background technology
In modern daily life and industrial production, the attrition and attack of metal material there will be at eachField, is one of two large major ways that destroy component of machine, engineering component, and corrosion will cause machineA large amount of consumption of tool part, wearing and tearing are to cause one of major reason of machine components inefficacy. TheyWhen a large amount of metal material of loss, also waste ample resources, in economic loss, occupied very largeProportion.
The inefficacy of the engineering component that high temperature, burn into friction and wear cause occurs in surface mostly, thisPhenomenon is impelled the very big concern of material science worker to material surface, and impels material surface modifying technologyFast development. People wish, when material monolithic keeps enough toughness and intensity, to make material listHigher, specific serviceability that face obtains, as wear-resisting, anti-corrosion and anti-oxidant etc.
It is reported, at present, in whole world industrialized country, the energy consuming in wearing and tearing accounts for gross energy1/2nd, approximately have 60%～80% component of machine because wearing and tearing were lost efficacy. Highly developed at oneIndustrialized country, the economic loss causing because of wearing and tearing every year almost accounts for 1%～2% of total value of production in national economy.For example, the economic loss that the U.S. causes due to wearing and tearing is every year on average up to 20,000,000,000 dollars; Britain every year on averageThe economic loss being caused by wearing and tearing exceedes 51,500 ten thousand pounds. In China, the economic loss being caused by wearing and tearingEqually also quite serious. Only according to department's rough Statistics such as oil, chemical industry, coal, electric power, agricultural machinery, IState just has every year up to the steel consumption of millions of tons in wearing and tearing, and economic loss reaches 200～30,000,000,000 yuanMore than. Thus, the effect of attrition of metal material performance quality and the service life of machine components, entersAnd affect the competitiveness of these machine components on market.
Meanwhile, metal erosion problem also spreads all over national economy every field, from the application of most advanced branches of science technologyTo industrial and agricultural production, the manufacture that is applied to national defense industry from daily life, every use metal materialPlace, all exist in varying degrees etching problem. According to relevant expert's statistics, each point, whole world halfJust there is one ton of steel to be etched into iron rust. For example, 1975, the economy that the U.S. is caused by corrosion was every year damagedLose up to 82,000,000,000 dollars, account for 4.9% of total value of production in national economy; Nineteen ninety-five, the U.S. is because corrosion causesEconomic loss straight line rise to 3,000 hundred million dollars. Statistics shows, in a country that industry is flourishing, because ofThe economic loss that causes of corrosion accounts for 2%～4% of total value of production in national economy, exceed floods, fire, earthquake,The summation of the loss causing with all natural calamities such as ancient measure of length, equal to 8 cun wind. Although China is only a developing country,But because the loss that corrosion brings is also considerable, annual about 5,000 hundred million yuans, account for state of China6% left and right of people's economical production total value. The economy only being caused by corrosion every year in oil and gas field is damagedLose with regard to approximately 10,000,000,000 yuan, the fund waste that coal industry is caused by corrosion is every year about 55.6 hundred million yuan, and electricNearly 1,700,000,000 yuan of the annual corrosion loss of power system.
Therefore,, from limited natural resources and energy resources, modern demand of industrial production component of machine hasEnough wear and corrosion behaviors, can extremely work long hours under rugged environment at high temperature, high load capacity etc.,Therefore the attrition and attack problem that solves metal is extremely urgent.
Laser melting coating cermet technology can be by obdurability high metal, good manufacturability and ceramic materialExcellent wear-resisting, anti-corrosion, the high temperature resistant and anti-oxidation characteristics of material combines, and is most worthy and competingStriving the surface strengthening technology of power, is also one of focus of laser melting and coating technique development.
Laser melting coating is the technology of emerging a, fast development, and it is at high-energy-density laser beam irradiationUnder, matrix surface skim melts with the alloy adding as required simultaneously, and forming thickness is 10～1000μ m surface melting layer, the process that rapid solidification requires to meet a certain property, is that set laser addsA new technology of the multidisciplinary intersection such as material reciprocation and rapid solidification moulding in heat fusing, molten bath,This technology obtains more careful research aspect surface treatment.
Because local surfaces is subject to heat density large, spot diameter is little, and heated time is short, therefore molten on surface of the workChange district very little, pass to inside workpiece heat few, in fusion zone, have very large thermograde, cooling velocityCan reach 104～109 DEG C/s. Just because of rapid solidification, give the feature that alloy is different from normal freezing. DoFor the laser melting coating of one of surface modification means, be suitable for top layer modification and the reparation of each metalloid. Laser tableFace cladding can keep former coating alloy composition (dilution rate 5～8%), only deposits at the intersection of reflow zone and matrixIn very limited phase diffusion zone, and this diffusion region realize just the metallurgical binding institute of coat and matrix mustMust. It is upper that it can be coated in common material (workpiece) high performance alloy powder, thereby obtain excellent specialThe face coat of property (as good coatings such as heat-resisting, anti-corrosion, wear-resisting, shock resistances).
Compared with traditional surface modification (thermal spraying, plasma spraying etc.) technology, it mainly contains following excellentPoint: interface is metallurgical binding; Organize superfine; Cladding layer composition is even and dilution factor is low; Coating thickness is controlled;Heat distortion is little; Easily realize constituency cladding and technical process and easily realize automation. In process for modifying surface, swashLight cladding has become more active research field.
Laser surface coating technology is the forward position in the material surface engineering field that grows up of middle nineteen seventiesOne of problem, both at home and abroad just flourish. Along with the development of superpower laser and supporting technology and completeKind, it progressively moves towards commercial Application from laboratory research, will have in following material surface modifying fieldPowerful vitality. Laser melting coating both can be used for the surface modification of traditional material, promoted the performance of material,Can be used for again the reparation of surface failure part, therefore available matrix material is very extensive, as carbon steel, alloySteel, cast iron and aluminium alloy, copper alloy, nickel base superalloy etc. In addition, material scientific research personnel also opensAmorphous state and quasi crystal coating etc. are sent out. At present, the modification on traditional material surface to laser technology both at home and abroadStudy morely, the research of high-alloy steel, high-temperature alloy surface modification also has report, but application laser is moltenThe practical engineering application of covering some components of machine of reparation but awaits further popularization, and main cause is sharpIn light cladding process, often there are the problems such as crackle, coating be inhomogeneous, await that scientific worker is further to grindStudy carefully.
That the state of laser melting coating layer material generally has is Powdered, thread, paste etc. In addition also can be by metalSheet material, sintered metal product, steel band and welding rod etc. are as cladding material, and wherein alloy powder is molten at laserIn coating technique, be most widely used.
Depending on the practical service environment condition difference of workpiece, also different to the performance requirement of surface coating.Cladding alloy system mainly contains ferrous alloy, nickel-base alloy, cobalt-base alloy and complex alloy powder etc.It is local wear-resisting and hold yielding part that iron(-)base powder is suitable for requirement; Nickel-base alloy is suitable for requirement partThe member of wear-resisting, heat and corrosion resistant and thermal fatigue resistance, required laser power density is than cladding ferrous alloySlightly high; Cobalt-base alloy coating is suitable for the part of wear-resisting, the anti-corrosion and thermal fatigue resistance of requirement; Ceramic coating is at heightUnder temperature, there is higher intensity, and Heat stability is good, chemical stability is high, is applicable to wear-resisting, anti-corrosion, resistance toThe part of high temperature and non-oxidizability.
Wear-resistant coating is in laser melting coating ceramic coating, to study to such an extent that be also maximum a kind the earliest. Ni base, CoAlthough base, Fe base self-fluxing alloy itself just have good wear-resisting, anti-corrosion, heat resistance, utilize themLaser cladding layer to carry out the research report of material surface strengthening a lot. But in slip, impact wearUnder the serious condition of abrasive wear, simple Ni base, Co base, Fe base self-melting alloy can not winAppoint instructions for use.
Composite is a kind of novel surface peening engineering material, metal and metal, metal and pottery,Pottery and pottery etc., the range of choice ten of the collocation between alloy powder and between alloy powder and potteryDivide extensively. Recent domestic has been carried out in the alloy powder system of above-mentioned laser melting coating and has been added one for this reasonDetermine various dystectic carbide, nitride, boride and the ceramic oxide particle of content, make goldBelong to the even pure ceramic coating of ceramic composite coating, to improve the wearability of cladding layer.
Can prepare high performance composite coating although adopt composite to carry out laser melting coating, at presentIn domestic most still research in laboratory, and its preparation technology adopts in laboratoryWith nickel-based self-fluxing alloy is mixed with the WC powder of certain content, then add saturated turpentine oil or fromSystem organic binder bond, furnishing slip or paste, precoating is overlying on workpiece, then carry out laser melting coating orSintering. Its hard particles adding is large, density is different from parent metal, and particle is in cladding layerDistribute often inhomogeneous, conventionally present gradient and distribute; The wetability of added granular materials and matrix, stableProperty, the coefficient of expansion and chemical reactivity etc. all cause the inhomogeneities of the microstructure and property of cladding layer. AndPrepared combination powder is because each constituent element proportion differs greatly, thereby in storage, transport and use procedureIn and easily produce segregation. Cannot carry out commercialization supply, on market, there is not yet at present particle and increaseThe merchandise sales of light laser cladding special powder. For above-mentioned reasons, there is not yet so far laser melting coating dedicated setClose powder, thereby restricted the application of laser melting coating on high abrasion operating mode field.
Summary of the invention
The object of the invention is to avoid above-mentioned deficiency of the prior art, by adding rare earth lanthanum oxide, excellentMetallization processes, develops a kind of further method of improving tungsten carbide of nickel-base coating, to improve at serious abrasive particleThe service life of the part of working under wear working condition condition.
The present invention proposes a kind of method of improving tungsten carbide of nickel-base laser cladding coating, it is characterized in that bagDraw together following steps:
Step 1 adds rare earth lanthanum oxide powder in tungsten carbide of nickel-base coated powder, the quality hundred of its componentProportion by subtraction is: lanthana 0.8%, and tungsten carbide 40%, Ni-based is 59.2%, and above-mentioned raw materials powder is placed in to sealingIn container, put into batch mixer mixing 1-3h;
Step 2, laser melting coating, taking common A3 steel as base material, is polished matrix with 400 order sand paper bright and clean,And with acetone soln wiping except surface and oil contaminant;
Step 3, is used semiconductor laser to carry out laser melting coating, and wherein laser power is 1500-1800w,Selected hot spot is wide is 5-10mm, and sweep speed is 1-2m/min, and protection gas is nitrogen, and throughput is15l/min, powder feeding rate is 3-10g/min.
The granularity of the lanthana in step 1 is 0.023～0.043mm, and the granularity of tungsten carbide is0.025～0.033mm, Ni-based particle mean size is 0.049～0.104mm.
The existing higher hardness of alloy powder for laser melting coating of the present invention, there is an excellent wearability and resistance to againCorrosivity, is specially adapted to the laser melting coating of the alloy workpiece of high surfaces hardness and high-wearing feature, andAnd can effectively prevent from producing because each constituent element proportion differs greatly in storage, transport and use procedureSegregation.
Brief description of the drawings
Fig. 1 is the SEM metallograph of the embodiment of the present invention 1;
Fig. 2 is the SEM metallograph of the embodiment of the present invention 2;
Fig. 3 is the SEM metallograph of the embodiment of the present invention 3.
Detailed description of the invention
Below in conjunction with detailed description of the invention, the invention will be further described.
Embodiment 1: a kind of technique and method of improving tungsten carbide of nickel-base laser cladding coating, comprises following stepRapid:
Technique and a method of improving tungsten carbide of nickel-base laser cladding coating, the percentage of its component is:The mass percent of its component is: lanthana 0.8%, tungsten carbide 40%, Ni-based 59.2%; The grain of lanthanaDegree is 0.023～0.043mm, and the granularity of tungsten carbide is 0.025～0.033mm, and Ni-based particle mean size is0.049～0.104mm。
1. above-mentioned raw materials powder is placed in to mixer mixing 1h.
2. laser melting coating is taking A3 steel as base material, bright and clean with 400 object sand paperings, removes surface with acetoneGreasy dirt. Laser power is 1500w, and employing spot size is 5mm, and sweep speed is 1m/min, protectionGas is nitrogen, and flow is 15l/min, and powder feeding rate is 3g/min.
3. after tested, gained coating layer thickness is 1mm, and hardness is 55HRC, and corrosion rate is 0.52g/m2*h,Metallurgical quality is good, and SEM metallograph as shown in Figure 1. :
Embodiment 2: a kind of technique and method of improving tungsten carbide of nickel-base laser cladding coating, comprises following stepRapid:
Technique and a method of improving tungsten carbide of nickel-base laser cladding coating, the percentage of its component is:The mass percent of its component is: lanthana 0.8%, tungsten carbide 40%, Ni-based 59.2%; The grain of lanthanaDegree is 0.023～0.043mm, and the granularity of tungsten carbide is 0.025～0.033mm, and Ni-based particle mean size is 0.049～0.104mm。
1. above-mentioned raw materials powder is placed in to mixer mixing 1.5h.
2. laser melting coating is taking medium carbon steel as base material, bright and clean with 400 object sand paperings, removes table with acetoneThe greasy dirt of face. Laser power is 1700w, and employing spot size is 6mm, and sweep speed is 1.5m/min,Overlap joint is 50%, and protection gas is argon gas, and flow is 15l/min, and powder feeding rate is 8g/min.
3. after tested, gained coating layer thickness is 1.2mm, and hardness is 57HRC, and corrosion rate is0.4952g/m2*h, metallurgical quality is good, and SEM metallograph is as shown in Figure 2.
Embodiment 3: a kind of technique and method of improving tungsten carbide of nickel-base laser cladding coating, comprises following stepRapid:: a kind of technique and method of improving tungsten carbide of nickel-base laser cladding coating, the percentage of its component is:The mass percent of its component is: lanthana 0.8%, tungsten carbide 40%, Ni-based 59.2%; The grain of lanthanaDegree is 0.023～0.043mm, and the granularity of tungsten carbide is 0.025～0.033mm, and Ni-based particle mean size is0.049～0.104mm。
1. above-mentioned raw materials powder is placed in to mixer mixing 2h.
2. laser melting coating is taking medium carbon steel as base material, bright and clean with 400 object sand paperings, removes table with acetoneThe greasy dirt of face. Laser power is 1800w, and employing spot size is 7mm, and sweep speed is 2m/min, protectsProtecting gas is nitrogen, and flow is 15l/min, and powder feeding rate is 10g/min.
3. after tested, gained coating layer thickness is 1.5mm, and hardness is 58HRC, and corrosion rate is0.4952g/m2*h, metallurgical quality is good, and SEM metallograph is as shown in Figure 3.
Claims (1)
1. a method of improving tungsten carbide of nickel-base laser cladding coating, is characterized in that, comprises following stepRapid:
Step 1 adds rare earth lanthanum oxide powder in tungsten carbide of nickel-base coated powder, the quality hundred of its componentProportion by subtraction is: lanthana 0.8%, and tungsten carbide 40%, Ni-based is 59.2%, and above-mentioned raw materials powder is placed in to sealingIn container, put into batch mixer mixing 1-3h;
Step 2, laser melting coating, taking common A3 steel as base material, is polished matrix with 400 order sand paper bright and clean,And with acetone soln wiping except surface and oil contaminant;
Step 3, is used semiconductor laser to carry out laser melting coating, and wherein laser power is 1500-1800W,Selected hot spot is wide is 5-10mm, and sweep speed is 1-2m/min, and protection gas is nitrogen, and throughput is15l/min, powder feeding rate is 3-10g/min;
The granularity of the lanthana in step 1 is 0.023～0.043mm, and the granularity of tungsten carbide is0.025～0.033mm, Ni-based particle mean size is 0.049～0.104mm.
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| CN104389924A (en) * | 2014-10-21 | 2015-03-04 | 刘永红 | Abrasion-resistant brake disc |
| CN109628927B (en) * | 2019-02-01 | 2020-10-16 | 水利部杭州机械设计研究所 | Wear-resistant corrosion-resistant nickel-based silicon carbide composite coating for maritime work hydraulic piston rod and preparation method thereof |
| CN109825833A (en) * | 2019-04-12 | 2019-05-31 | 上海海事大学 | A kind of rare earth modified WC-Ni base coating and preparation method thereof |
| CN113652686A (en) * | 2021-08-10 | 2021-11-16 | 江苏智远激光装备科技有限公司 | Nickel-based tungsten carbide laser cladding process for nickel-aluminum bronze surface |
| CN113652688B (en) * | 2021-08-18 | 2023-09-29 | 江苏智远激光装备科技有限公司 | Laser cladding nickel-based tungsten carbide technology for copper alloy core glass mold |
| CN114959686B (en) * | 2022-05-27 | 2023-07-21 | 宜宾上交大新材料研究中心 | Laser cladding powder and method for laser cladding on aluminum alloy surface |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818343A (en) * | 2010-04-21 | 2010-09-01 | 广州有色金属研究院 | Laser cladding method of composite coating containing spherical tungsten carbide |
| CN102962447A (en) * | 2012-11-20 | 2013-03-13 | 汕头大学 | Titanium carbide metal ceramic powder and method for laser cladding of powder |
| CN103286310A (en) * | 2013-06-01 | 2013-09-11 | 江苏新亚特钢锻造有限公司 | Particle-reinforced laser cladding alloy powder and preparation method thereof |
-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101818343A (en) * | 2010-04-21 | 2010-09-01 | 广州有色金属研究院 | Laser cladding method of composite coating containing spherical tungsten carbide |
| CN102962447A (en) * | 2012-11-20 | 2013-03-13 | 汕头大学 | Titanium carbide metal ceramic powder and method for laser cladding of powder |
| CN103286310A (en) * | 2013-06-01 | 2013-09-11 | 江苏新亚特钢锻造有限公司 | Particle-reinforced laser cladding alloy powder and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 添加CeO2激光熔覆Ni基WC金属陶瓷涂层的高温干摩擦磨损性能;匡建新等;《材料热处理技术》;20110228;第40卷(第4期);全文 * |
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