A kind of preparation method being sintered iron powder base soft-magnetic composite material
Technical field
The invention belongs to soft-magnetic composite material technical fields, are related to a kind of with iron powder steam treatment, Double cone spray formula bonding
The method that change processing, warm mold high speed compacting and low-temperature sintering combine preparation sintering soft-magnetic composite material.
Background technique
Iron powder base soft-magnetic composite material by powder particle surface carry out insulating processing, then use powder metallurgical technique
A kind of electromagnetic application material of preparation.The resistivity of soft-magnetic composite material is high, and eddy-current loss is low in alternating magnetic field, be suitable for compared with
It is used under high-frequency, in electrician, electric power and electronic equipment, as electromagnet core, breaker iron core, transformer core, motor are fixed
There is important application in the fields such as the iron core of son and rotor.Traditional iron powder base soft-magnetic composite material passes through organic and inorganic materials
Cladding obtain insulating layer, then use compression moulding, be not necessarily to high temperature sintering, since the intensity of material is low, it is multiple to limit soft magnetism
The popularization and application of condensation material.
The present invention is using iron powder steam treatment, the processing of Double cone spray formula cohesion, warm mold high speed compacting and low-temperature sintering
The technique preparation sintering iron powder base soft-magnetic composite material combined.Steam treated is carried out to ferrous powder granules first, in particle surface
Form one layer of very thin Fe3O4Oxidation film is coated, plays the role of interface diffusion barrier layer and hinders counterdiffusion between matrix and Si.
Then fine silicon powder and ferrophosphor(us) powder are evenly coated at by ferrous powder granules surface using cohesion technique.Finally using temperature
The forming of mould high velocity compacting technique, obtains highdensity green compact, promotes the diffusion of element.Powder high velocity compacted is to utilize weight high speed
The enormous impact wave energy that impact generates densifies metal powder in a short period of time, has pressing speed height, green compact close
The advantage that degree is high and Density Distribution is uniform, elastic after effect and knockout press are low, and repeat impact compacting can be carried out, further mention
High green density.By adding ferrophosphor(us), low melting point eutectic phase, the liquid formed in sintering process are formed at a lower temperature
Phase acceleration of sintering process, solve under high temperature sintering Si element in the base quick diffusion-homogenization and cannot be formed has high electricity
The interface iron silicon phase of resistance rate, the problem of increasing eddy-current loss.It is equal to be sintered ferrous powder granules surface in iron powder base soft-magnetic composite material
The iron silicon phase of even one layer thin of cladding, has ferromagnetic atomic ordered structure and high resistivity, reduces the vortex damage of composite material
Consumption, the presence of oxide layer hinder in sintering process Si atom to the diffusion inside iron particle.Resulting sintering iron powder base soft magnetism
Composite material had not only had the characteristics that soft-magnetic composite material eddy-current loss was low, but also had high excellent of sintering soft-magnetic composite material intensity
Point.
Summary of the invention
The purpose of the present invention is to provide a kind of methods for preparing sintering iron powder base soft-magnetic composite material, it is intended to improve iron powder
Consistency, magnetic conductivity and the intensity of base soft-magnetic composite material.
A kind of preparation process being sintered iron powder base soft-magnetic composite material, specific process step have:
1, iron powder steam treatment: using 80-180 μm of water atomized iron powder as raw material, powder is at 570~1150 DEG C, Yu Shui
1~6h of surface oxidation treatment is carried out in vapor atmosphere, the iron powder after steam treatment is 1-5 hours dry at 80-120 DEG C, obtains pre-
Handle iron powder.
2, mixed-powder cohesion is handled: by pretreatment powder and 0.1-5 μm of ultra-fine pure silicon powder and 1-5 μm of ultra-fine iron
Phosphorus alloy powder premixing uniformly, obtains mixed-powder.Mixed-powder carries out cohesion processing in Double cone spray blender, first
First by binder 60~100 DEG C at a temperature of be dissolved in solvent, form binder solution, binder solution is heated to 80-
100 DEG C, then enter in Double cone spray blender under the carrying of high pressure gas, binder solution is atomized and is uniformly sprayed at
On the material constantly to roll, 1-5h is mixed, obtains cohesion processing powder.
Wherein the phosphorus content in ferrophosphor(us) is 15-23%.
The binder is butadiene-styrene rubber, neoprene or polyethylene wax, ethylene bis stearic acid amide, stearic acid, gathers
One or more of amide waxe, microwax.
The solvent be one of gasoline, toluene, dimethylbenzene, chloroform, methylene chloride, normal heptane and alcohol or
It is several.
The content of binder is 0.05wt%~10wt% in the binder solution, and the solution temperature of binder is
60-90℃。
The Double cone spray blender band heating jacket, is heated, heating temperature is 80 DEG C~180 using conduction oil
DEG C, pressure is (0.8-0.9) × 10 in blender-5Pa.The rotational speed of mixing machine is 100-200 revs/min, the center of blender
Atomizer is arranged in position, and high pressure gas carries binder solution and is atomized at nozzle, atomization pressure 0.1-0.5MPa,
The flow of atomization binder is 0.1-0.5 ls/h.The heating temperature of binder is 100-200 DEG C, incorporation time 1-5
Hour.
3, warm mould high velocity compacted: bonded iron-based powder is suppressed on high-rate forming press, press strokes 30-
70mm, corresponding rate of suppressing is 6.2-9.4m/s, and compacting energy is 795-1855J.Use lithium stearate alcohol suspension as
Die wall lubricant, is applied to high speed press upper punch surface and die cavity inner surface carries out die wall lubrication.Former uses digital temperature control
Silica gel piece is heated, and heating temperature is 60 DEG C -150 DEG C, and the former that iron silicon phosphorus mixed-powder is sent into heating is carried out Wen Mogao
Ram compression system can carry out repeat impact compacting, and point 2~3 Secondary Shocks obtain soft-magnetic composite material green body.
4, sintering densification: soft-magnetic composite material green body carries out low-temperature short-time sintering, sintering temperature in flowing hydrogen atmosphere
Degree is 900 DEG C -1200 DEG C, soaking time 10-30min.It is cooling with the speed of 1-3 DEG C/min after heat preservation, obtain iron powder
Base soft-magnetic composite material.
The present invention has the advantages that water atomized iron powder forms Fe after vapor high-temperature process3O4Film can prevent
Water atomized iron powder end surface continues to aoxidize, while being able to maintain certain magnetism;Cohesion is carried out using Double cone spray blender
Processing, binder is atomized under the action of high pressure gas, comes into full contact with the material stirred, by ultra-fine pure silicon powder and ultra-fine iron
Phosphorus alloy powder uniform adhesion obtains bonded iron-based powder on ferrous powder granules surface.From iron powder is during heating mixing
To processing hardening is reduced, soft annealing effect effectively improves compressibility.It is in negative pressure, easy volatile solvent and barrel in blender
Steam is formed after contact, steam is extracted out by vacuum pump, improves rate of drying.Warm mould high velocity compacting technique can effectively improve pressure
Base density reduces intergranular air gap distribution, improves the magnetic conductivity and saturation induction density of material;What is uniformly coated is ultra-fine pure
Silicon powder and ultra-fine iron phosphorus powder form low melting point eutectic phase under lower sintering temperature, reduce sintering temperature, obtain one layer high electricity
The clad of resistance rate, clad is complete, reduces eddy-current loss, improves the consistency and intensity of composite material.
Detailed description of the invention
Fig. 1 is process flow chart of the invention.
Fig. 2 is the schematic diagram of Double cone spray blender.
The names of the parts are as follows in figure:
1 is support shaft, and 2 be mixing tank, and 3 be interlayer, and 4 be vacuum tube, and 5 be nozzle, and 6 be discharge port, and 7 be high pressure gas, 8
It is pedestal for motor, 9,10 be conduction oil.
Specific embodiment
Embodiment 1:Fe-3.5%Si-1.5%P soft-magnetic composite material preparation process
Using 150 μm of water atomized iron powder, 3 μm of ultra-fine pure silicon powder and 5 μm of ultra-fine ferrophosphor(us) powder as raw material,
Phosphorus content in middle ferrophosphor(us) is 23%.Water atomized iron powder end carries out at surface oxidation in water vapour atmosphere at 950 DEG C
3h is managed, the iron powder after steam treatment is 1 hour dry at 110 DEG C, obtains pretreatment iron powder;Will pretreatment iron powder and pure silicon powder and
The premixing of ferrophosphor(us) powder uniformly, obtains mixed-powder.Mixed-powder carries out cohesion processing in Double cone spray blender.
Binder is butadiene-styrene rubber, and solvent is methylene chloride.In binder solution the content of binder be 0.3wt%, binder it is molten
Solving temperature is 80 DEG C.First by binder 80 DEG C at a temperature of be dissolved in solvent, formed binder solution, binder solution quilt
90 DEG C are heated to, is then entered in Double cone spray blender under the carrying of high pressure gas, binder solution is atomized simultaneously uniformly
It is sprayed on the material constantly to roll, mixes 2h, obtain cohesion processing powder.The heating temperature of Double cone spray blender is
120 DEG C, pressure is 0.85 × 10 in blender-5Pa.The rotational speed of mixing machine is 150 revs/min, and atomization pressure is
0.15MPa, the flow of atomization binder are 0.2 l/h.Bonded iron-based powder is pressed on high-rate forming press
System, press strokes 60mm, corresponding rate of suppressing is 8.7m/s, and compacting energy is 1590J.With lithium stearate alcohol suspension
As die wall lubricant, it is applied to high speed press upper punch surface and die cavity inner surface carries out die wall lubrication.Former is using number
Temperature control silica gel piece is heated, and heating temperature is 100 DEG C, and the former that iron silicon phosphorus mixed-powder is sent into heating is carried out warm mould high speed
Compacting carries out one-shot compacting, obtains soft-magnetic composite material green body.Soft-magnetic composite material green body in flowing hydrogen atmosphere into
Row sintering, sintering temperature are 970 DEG C, soaking time 20min.It is cooling with the speed of 3 DEG C/min after heat preservation, obtain iron powder
Base soft-magnetic composite material.
Embodiment 2:Fe-6.5%Si-2.0%P soft-magnetic composite material preparation process
Using 180 μm of water atomized iron powder, 2 μm of ultra-fine pure silicon powder and 3 μm of ultra-fine ferrophosphor(us) powder as raw material,
Wherein the phosphorus content in ferrophosphor(us) is 21%.Water atomized iron powder end carries out surface oxidation at 900 DEG C in steam atmosphere
1h is handled, the iron powder after steam treatment is 1.5 hours dry at 120 DEG C, obtains pretreatment iron powder;It will pretreatment iron powder and pure silicon powder
End and the premixing of ferrophosphor(us) powder uniformly, obtain mixed-powder.Mixed-powder carries out cohesion in Double cone spray blender
Processing.Binder is polyethylene wax, and solvent is normal heptane.The content of binder is 0.4wt% in binder solution, binder
Solution temperature is 60 DEG C.First by binder 60 DEG C at a temperature of be dissolved in solvent, formed binder solution, binder solution
80 DEG C are heated to, is then entered in Double cone spray blender under the carrying of high pressure gas, binder solution is atomized simultaneously
It is even to be sprayed on the material constantly to roll, 1.5h is mixed, cohesion processing powder is obtained.The heating temperature of Double cone spray blender
It is 130 DEG C, pressure is 0.8 × 10 in blender-5Pa.The rotational speed of mixing machine is 200 revs/min, and atomization pressure is
0.3MPa, the flow of atomization binder are 0.3 l/h.Bonded iron-based powder is suppressed on high-rate forming press,
Press strokes are 70mm, and corresponding rate of suppressing is 9.4m/s, and compacting energy is 1855J.Made with lithium stearate alcohol suspension
For die wall lubricant, it is applied to high speed press upper punch surface and die cavity inner surface carries out die wall lubrication.Former is using number temperature
Control silica gel piece is heated, and heating temperature is 90 DEG C, and the former that iron silicon phosphorus mixed-powder is sent into heating is carried out Wen Mogao ram compression
System carries out one-shot compacting, obtains soft-magnetic composite material green body.Soft-magnetic composite material green body carries out in flowing hydrogen atmosphere
Sintering, sintering temperature are 1050 DEG C, soaking time 15min.It is cooling with the speed of 3 DEG C/min after heat preservation, obtain iron powder
Base soft-magnetic composite material.
Embodiment 3:Fe-4.0%Si-2.5%P soft-magnetic composite material preparation process
Using 100 μm of water atomized iron powder, 5 μm of ultra-fine pure silicon powder and 1 μm of ultra-fine ferrophosphor(us) powder as raw material,
Wherein the phosphorus content in ferrophosphor(us) is 22%.Water atomized iron powder end carries out Surface Oxygen at 1050 DEG C in steam atmosphere
Change processing 1h, the iron powder after steam treatment is 1 hour dry at 100 DEG C, obtains pretreatment iron powder;It will pretreatment iron powder and pure silicon powder
End and the premixing of ferrophosphor(us) powder uniformly, obtain mixed-powder.Mixed-powder carries out cohesion in Double cone spray blender
Processing.Binder is polyethylene wax, ethylene bis stearic acid amide and stearic blend.Solvent is chloroform, normal heptane
With the mixed solvent of alcohol.The content of binder is 0.2wt% in binder solution, and the solution temperature of binder is 85 DEG C.It is first
First by binder 85 DEG C at a temperature of be dissolved in solvent, form binder solution, binder solution is heated to 95 DEG C, then
Enter in Double cone spray blender under the carrying of high pressure gas, binder solution, which is atomized and is uniformly sprayed at, constantly to roll
On material, 2h is mixed, obtains cohesion processing powder.The heating temperature of Double cone spray blender is 140 DEG C, pressure in blender
It is 0.9 × 10-5Pa.The rotational speed of mixing machine is 140 revs/min, atomization pressure 0.25MPa, atomization binder
Flow is 0.4 l/h.Bonded iron-based powder is suppressed on high-rate forming press, and press strokes are 30mm and 40mm,
Corresponding compacting rate is respectively 6.2m/s and 7.1m/s, and compacting energy is respectively 795J and 1060J.It is outstanding with lithium stearate alcohol
Supernatant liquid is applied to high speed press upper punch surface and die cavity inner surface carries out die wall lubrication as die wall lubricant.Former uses
Digital temperature control silica gel piece is heated, and heating temperature is 110 DEG C, and the former that iron silicon phosphorus mixed-powder is sent into heating is carried out Wen Mo
High velocity compacted carries out secondary pulse compacting, obtains soft-magnetic composite material green body.Soft-magnetic composite material green body is in flowing hydrogen atmosphere
In be sintered, sintering temperature be 1070 DEG C, soaking time 30min.It is cooling with the speed of 1 DEG C/min after heat preservation, it obtains
To iron powder base soft-magnetic composite material.
Embodiment 4:Fe-10%Si-3.0%P soft-magnetic composite material preparation process
Using 75 μm of water atomized iron powder, 5 μm of ultra-fine pure silicon powder and 5 μm of ultra-fine ferrophosphor(us) powder as raw material,
Phosphorus content in middle ferrophosphor(us) is 23%.Water atomized iron powder end carries out surface oxidation at 1100 DEG C in steam atmosphere
1h is handled, the iron powder after steam treatment is 1 hour dry at 120 DEG C, obtains pretreatment iron powder;It will pretreatment iron powder and pure silicon powder
Uniformly with the premixing of ferrophosphor(us) powder, mixed-powder is obtained.Mixed-powder carries out at cohesion in Double cone spray blender
Reason.Binder is the blend of ethylene bis stearic acid amide, stearic acid and microwax.Solvent is methylene chloride, normal heptane and wine
The mixed solvent of essence.The content of binder is 0.3wt% in binder solution, and the solution temperature of binder is 90 DEG C.First will
Binder 90 DEG C at a temperature of be dissolved in solvent, formed binder solution, binder solution is heated to 95 DEG C, then in height
Calm the anger body carrying under enter in Double cone spray blender, binder solution is atomized and is uniformly sprayed at the material constantly to roll
On, 2h is mixed, cohesion processing powder is obtained.The heating temperature of Double cone spray blender is 110 DEG C, and pressure is in blender
0.8×10-5Pa.The rotational speed of mixing machine is 180 revs/min, atomization pressure 0.1MPa, the atomization flow of binder
It is 0.25 l/h.Bonded iron-based powder is suppressed on high-rate forming press, press strokes 65mm, corresponding to press
Rate processed is 9.1m/s, and compacting energy is 1722.5J.It uses lithium stearate alcohol suspension as die wall lubricant, is applied to height
Ram compression machine upper punch surface and die cavity inner surface carry out die wall lubrication.Former is heated using digital temperature control silica gel piece, is heated
Temperature is 100 DEG C, and the former that iron silicon phosphorus mixed-powder is sent into heating is carried out warm mould high velocity compacted, carries out one-shot compacting,
Obtain soft-magnetic composite material green body.Soft-magnetic composite material green body is sintered in flowing hydrogen atmosphere, sintering temperature 1110
DEG C, soaking time 10min.It is cooling with the speed of 2 DEG C/min after heat preservation, obtain iron powder base soft-magnetic composite material.