Brake pad material and preparation technology thereof for a kind of high-power wind turbine unit
Technical field
The invention belongs to wind-powered electricity generation unit brake material preparing technical field, be specifically related to brake pad material and preparation technology thereof for a kind of high-power wind turbine unit.
Background technology
Fast development along with Wind Power Generation Industry, wind-powered electricity generation unit is towards high speed, the high future development carrying, it is the one of the main reasons that wind-powered electricity generation unit produces fault that wind-powered electricity generation unit brakes brake lining damages, because the coefficient of friction of general brake lining material is low and frictional behaviour is unstable, heat resisting temperature during work is low, life cycle is short, and inefficiency seriously restricts the raising of the generating efficiency of wind-powered electricity generation unit.
Application number is the preparation technology > > of a patent < < copper-base powder metallurgy brake pad for high-power wind turbine generator sets of 200910311183.8, in raw material, contain aviation kerosine and graphite, under regular situation, the auxiliary graphite of aviation kerosine can play good lubricant effect, but while braking under the high temperature and high speed work of high-power wind turbine unit, the impurity that graphite is introduced due to lattice defect own can make brake lining when braking, produce a large amount of frictional heats, cause oil film attenuate, affect coefficient of friction, reduced brake lining braking ability, this technique is higher to graphite purity requirement, and high purity graphite and aviation kerosine have increased production cost greatly, although technique adopts pressure sintering, makes material have higher heat resistance, material is after sintering, and annealing is serious, and hardness and the intensity of material all reduce, and pressurization had both increased energy consumption, and the tin of low melting point also is easily extruded out, has reduced material property.
Summary of the invention
The present invention is in order to make up the deficiencies in the prior art, brake pad material and preparation technology thereof for a kind of high-power wind turbine unit is provided, this material has stablizes suitable friction factor, and intensity is high, and wearability is good, specific heat capacity and the density of material are large, can effectively bear the peakload in operating condition, good heat conductivity, functional reliability is high, long service life, has significantly improved the generating efficiency of blower fan.
A high-power wind turbine unit brake pad material, its composition and quality percentage composition thereof are: Cu:39.8 ~ 41.5%, Fe:6.6 ~ 8.2%, Fe
2b:3.3 ~ 3.5%, FeB:1.5 ~ 1.9%, Al
2o
3: 6.4 ~ 6.6%, SiO
2: 6.4 ~ 6.6%, graphite: 17.5 ~ 18.8%, glass fibre: 4.8 ~ 5.7%, glass dust: 4 ~ 4.5%, fine SiO
2: 2.4 ~ 2.9%, residue: other.
Described high-power wind turbine unit brake pad material, its raw materials used comprising: 200 100 parts of order electrolytic copper powders, 24 ~ 27 parts of reduced iron powders, 16 parts of 200 order Alundums, 16 parts of natural siliceous sands, 12 ~ 13 parts of 200 order ferro-borons, 43 ~ 45 parts of 50 order crystalline flake graphites, 12 ~ 14 parts, glass fibre, 10 ~ 11 parts, 600 order glass dust, fine SiO
26 ~ 7 parts of particles, described part refers to mass parts.
The preparation technology of brake pad material for described high-power wind turbine unit, comprises the following steps:
1. green compact preparation: add after mixing in proportion in mould, be pressed into green compact;
2. sintering: green compact are overlayed on the steel backing after copper plating treatment, carry out vacuum heating-press sintering, pressure is 9 ~ 12MPa, 840 ~ 890 ℃ of sintering temperatures, heat-insulation pressure keeping 2.5 ~ 3.5h is cooling with stove;
3. subsequent treatment: heat by gas burner at material surface, temperature is at 950 ~ 1000 ℃, and insulation 10min, is processed into required form after room temperature is cooling.
Because the intensity of brake lining material and wearability depend on structure and the physicochemical property with matrix to a great extent, therefore add reduced iron powder combination in electrolytic copper powder of the present invention, in sintering process, can form solid solution reinforced alloys, have continuously and firmly metal connect phase, effectively improve the intensity of copper matrix.Add Alundum (Al
2o
3>=99.5%) and natural siliceous sand (SiO
2>=97%) carry out the compound conduct friction of 1:1 particle, friction factor stability is higher, effectively prevents that matrix from flowing when high temperature, reduces surperficial bonding and clamping stagnation, gives mechanical strength and hardness that matrix is suitable.Add ferro-boron can increase the coefficient of stability, reduce the wearing and tearing of antithesis, meet the work under high temperature high power condition, ferro-boron and reduced iron powder produce superfine high rigidity interstitial compound when sintering, disperse is in matrix, when matrix is carried out to dispersion-strengthened action, fine grain reactant reduces friction material abrasive action.
In crystalline flake graphite layer, atomic binding forces is very strong, and between layers in conjunction with very weak, be easy to dissociate along interlayer, isolate thin layer, therefore there is good greasy property, can improve the wearability of matrix, and glass fibre and matrix have good wetability and associativity firmly, can strengthen the adjacent interplanar adhesion of graphite crystal, prevent from longitudinally bending or depression in Frictional Slipping.Because glass fibre has higher fusing point and discrete heat, when sintering process and use, there is not crystal transfer yet, therefore can improve the stability of material, reduce or eliminate cracking, the rub resistance of reinforcing material and heat resistance greatly, make material obtain good mechanical strength and high hardness, improve its physical and mechanical property.Glass dust, when softening, has the advantages that hardness high-wearing feature is good, and the softening rear skin covering of the surface that forms is filled surface crater, plays the effect of lubricated and stable friction factor at friction surface, can effectively regulate bonding degree; When adding 10 ~ 11 parts, in matrix, be uniformly dispersed, without clustering phenomena, do not affect the continuity of matrix material, can obtain best lubricant effect.Recharge fine SiO
2particle, is further enhanced the integrality of material surface solid lubricant film and intensity, improves properties of antifriction and wear resistance and the resistance to elevated temperatures of composite.
The raw materials used fine silt that all adopts suitable order number in invention, while improving compacting, contact surface is large, amount of contraction is large, be convenient to be pressed into green compact, powder has larger surface energy, has more high activity in sintering process, and in sintering, diffusion velocity is fast, can obtain larger distortion of lattice, make the material making there is higher intensity.Green compact overlay on the steel backing after copper plating treatment, carry out vacuum heating-press sintering, adopt the treatment process that is incubated 2.5 ~ 3.5h at 9 ~ 12MPa, 840 ~ 890 ℃, can form (FeB+Fe
2b) biphasic or bipolar type boride layer, improve hardness and the wearability of material, the heat treated of follow-up gas burner, in the situation that can guarantee that the heat distortion amount of material is little, make material surface form the oxide-film of 50 ~ 80um, cooling along with material, austenite changes martensite into, make material surface hardened, residual certain compression in while hardened layer, thereby wearability and the fatigue resistance of raising material.
Wind-powered electricity generation unit brake pad material of the present invention, by studying the mechanism of action of each component, carry out rational proportion, Optimizing Process Parameters, regulate content and the existence form of controlling each component, make brake lining carrying rationally, perfect heat-dissipating, gained brake pad has and stablizes suitable friction factor with material, intensity is high, wearability is good, specific heat capacity and the density of material are large, in unit volume, can absorb more frictional heat, can effectively bear the peakload in operating condition, good heat conductivity, high temperature resistant during military service, functional reliability is high, the materials'use life-span is long, reduced maintenance frequency, significantly improved the generating efficiency of blower fan.
Specific embodiment
Embodiment mono-
A preparation technology for brake pad material for high-power wind turbine unit, comprises the following steps:
1. green compact preparation: by 100 part of 200 order electrolytic copper powder, 24 parts of reduced iron powders, 16 part of 200 order Alundum, 16 parts of natural siliceous sands, 12 part of 200 order ferro-boron, 43 part of 50 order crystalline flake graphite, 12 parts of glass fibres, 10 part of 600 order glass dust, 6 parts of fine SiO
2particle, adds in mould after mixing in proportion, and is pressed into green compact;
2. sintering: green compact are overlayed on the steel backing after copper plating treatment, carry out vacuum heating-press sintering, pressure is 9MPa, 840 ℃ of sintering temperatures, heat-insulation pressure keeping 2.5h is cooling with stove;
3. subsequent treatment: heat by gas burner at material surface, temperature is at 950 ℃, and insulation 10min, is processed into required form after room temperature is cooling.
After testing, the composition of this material and quality percentage composition thereof are: 39.8%Cu, 7.5%Fe, 3.3%Fe
2b, 1.9%FeB, 6.4%Al
2o
3, 6.4%SiO
2, 18.8% graphite, 5.2% glass fibre, 4.3% glass dust, 2.9% fine SiO
2, residue: other.
Embodiment bis-
A preparation technology for brake pad material for high-power wind turbine unit, comprises the following steps:
1. green compact preparation: by 100 part of 200 order electrolytic copper powder, 26 parts of reduced iron powders, 16 part of 200 order Alundum, 16 parts of natural siliceous sands, 13 part of 200 order ferro-boron, 44 part of 50 order crystalline flake graphite, 13 parts of glass fibres, 10 part of 600 order glass dust, 7 parts of fine SiO
2particle, adds in mould after mixing in proportion, and is pressed into green compact;
2. sintering: green compact are overlayed on the steel backing after copper plating treatment, carry out vacuum heating-press sintering, pressure is 10.5MPa, 865 ℃ of sintering temperatures, heat-insulation pressure keeping 3.0h is cooling with stove;
3. subsequent treatment: heat by gas burner at material surface, temperature is at 980 ℃, and insulation 10min, is processed into required form after room temperature is cooling.
After testing, the composition of this material and quality percentage composition thereof are: 40.7%Cu, 8.2%Fe, 3.5%Fe
2b, 1.7%FeB, 6.5%Al
2o
3, 6.5%SiO
2, 17.5% graphite, 5.3% glass fibre, 4.5% glass dust, 2.7% fine SiO
2, residue: other.
Embodiment tri-
A preparation technology for brake pad material for high-power wind turbine unit, comprises the following steps:
1. green compact preparation: by 100 part of 200 order electrolytic copper powder, 27 parts of reduced iron powders, 16 part of 200 order Alundum, 16 parts of natural siliceous sands, 13 part of 200 order ferro-boron, 45 part of 50 order crystalline flake graphite, 14 parts of glass fibres, 11 part of 600 order glass dust, 7 parts of fine SiO
2particle, adds in mould after mixing in proportion, and is pressed into green compact;
2. sintering: green compact are overlayed on the steel backing after copper plating treatment, carry out vacuum heating-press sintering, pressure is 12MPa, 890 ℃ of sintering temperatures, heat-insulation pressure keeping 3.5h is cooling with stove;
3. subsequent treatment: heat by gas burner at material surface, temperature is at 1000 ℃, and insulation 10min, is processed into required form after room temperature is cooling.
After testing, the composition of material and quality percentage composition thereof are: 41.5%Cu, 6.6%Fe, 3.4%Fe
2b, 1.5%FeB, 6.6%Al
2o
3, 6.6%SiO
2, 17.9% graphite, 5.7% glass fibre, 4% glass dust, 2.4% fine SiO2, residue: other.
The performance that detects above-mentioned three embodiment resulting materials, testing result is as shown in the table:
Test item |
Embodiment mono- |
Embodiment bis- |
Embodiment tri- |
Coefficient of friction |
0.39 |
0.42 |
0.41 |
Wear rate (mm/ face) |
0.0092 |
0.0087 |
0.0089 |
Wear extent (cm
3/GJ)
|
65 |
63 |
66 |
Specific heat capacity: J/ (kg ℃) |
193 |
196 |
197 |
Density (10e
-6kg/mm3)
|
1.17 |
1.19 |
1.17 |
The coefficient of heat conduction (W/mk) |
2.80 |
2.79 |
2.83 |
As seen from the above table, this method gained brake pad has and stablizes suitable friction factor with material, specific heat capacity and the density of material are large, in unit volume, can absorb more frictional heat, effectively bear the peakload in operating condition, good heat conductivity, high temperature resistant during military service, increase work efficiency, extended service life.