A kind of preparation method of dispersion-strengthened aluminum matrix composite
Technical field
The invention belongs to aluminum matrix composite preparing technical field, a kind of preparation method of nano particle dispersion-strengthened aluminum matrix composite is particularly provided.
Technical background
Excellent physicals and the mechanical properties such as that aluminum matrix composite has is lightweight, specific tenacity is high, specific modulus is high, thermal expansivity is low, high temperature resistant, wear-resistant, dimensional stabilizing, are widely used in the fields such as aerospace, military and national defense and communications and transportation, Electronic Packaging.Wherein, dispersion-strengthened aluminum matrix composite has the features such as cost is low, preparation technology simple, performance is more outstanding, becomes gradually the study hotspot in domestic and international aluminum matrix composite field.Conventional dispersion-strengthened aluminum matrix composite technology of preparing has powder metallurgic method and two kinds of techniques of casting.The complex process equipment of powder metallurgic method, high expensive, be difficult for preparation large volume and complex-shaped part, and have in process of production the danger such as dust-firing and blast.And casting technique is simple, easy to operate, can prepare the matrix material of large volume, equipment investment is few, and production cost is low, and productivity is high, suitability for industrialized scale production.
Traditional aluminum matrix composite is that enhanced granule is applied in aluminum substrate, due to additional particle in aluminum substrate, to exist between enhanced granule and matrix wettability poor, surface reaction is difficult to control, and the defects such as enhanced granule skewness have affected the performance of aluminum matrix composite.How to improve the wettability between enhanced granule and matrix, improve the interface performance of material, become when previous problem demanding prompt solution.
High-energy ultrasonic method be a kind of by nanoparticulate dispersed to the effective ways in aluminium alloy melt.High-energy ultrasonic ratio juris is to utilize stirring in sound cavitation effect and the caused mechanics effect of acoustic streaming effect that ultrasonic wave produces in aluminium alloy melt, dispersion, degasification etc. to be used for promoting nano particle to sneak into aluminium alloy melt; improve the wettability between nano particle and aluminium alloy melt, force nano particle dispersed in aluminium alloy melt.High-energy ultrasonic method is the preparation method of a kind of simple process, dispersion-strengthened aluminum matrix composite with low cost.But, according to conventional cast technique, single enhanced granule is applied in aluminium alloy melt, in high-energy ultrasonic dispersion process, most of enhanced granule can float over bath surface or adhere to smelting pot inwall, is difficult for dispersed entering in whole aluminium alloy melt.Therefore, disperse inhomogeneously in the final aluminum matrix composite obtaining in enhanced granule macroscopic view, consistency of performance is poor.
Summary of the invention
The object of the invention is to overcome in the aluminum matrix composite that prior art exists, in enhanced granule macroscopic view, disperse inhomogeneous, the problem that consistency of performance is poor, a kind of preparation method of dispersion-strengthened aluminum matrix composite is provided, make it solve dispersion-strengthened aluminum matrix composite in the past and have fragility phase and the inhomogeneous defect of distribution of material, nano level Al
2o
3particle is uniformly distributed in matrix, has played dispersion-strengthened action, and the strength and modulus of matrix is improved significantly.
A preparation method for dispersion-strengthened aluminum matrix composite, first adopts sol-gel method to prepare CuO/Al
2o
3nano composite powder, makes nanometer Al
2o
3mix with CuO uniform particles, to ensure nanometer Al
2o
3the follow-up abundant dispersion of particle enters aluminium alloy melt inside, then adopts high-energy ultrasonic legal system for dispersion-strengthened aluminum matrix composite.Concrete grammar comprises following content:
1, sol-gel method is prepared CuO/Al
2o
3nano composite powder
(1) with soluble copper salt and exsiccated ammonium alum (NH
4al (SO
4)
2) be raw material, be mixed with the aqueous solution of 0.1~25 mol/L as reaction mother liquor, prepare certain density bicarbonate of ammonia (NH
4hCO
3) solution is as precipitation agent, according to CuO/Al
2o
3middle Al
2o
3content is determined mantoquita and exsiccated ammonium alum (NH
4al (SO
4)
2) amount, according to NH
4al (SO
4)
2with NH
4hCO
3mol ratio be 1:4 and Cu
2+with NH
4hCO
3mol ratio be that 1:2 determines NH
4hCO
3amount.
(2) precipitant solution is added in reaction mother liquor, in reaction system, add 0.5~1.0 mol/L NH simultaneously
3h
2it is neutral that O regulation system pH value remains, after lasting stirring 10~60 min, ultrasonic dispersion 5~30 min obtain the water-sol, and stirring velocity is 100~500 r/min, and ultrasonic power is 100~1000 W.
(3) by after above-mentioned gained water-sol ageing 10~24 h, remove supernatant liquid, after centrifuge dehydration, obtain gel.After gel being dried at 80 DEG C, pulverize, in 500~800 DEG C of air, calcine 60~120 min and obtain CuO/Al
2o
3nano composite powder.
2, high-energy ultrasonic legal system is for dispersion-strengthened aluminum matrix composite
(1) technical pure aluminum or aluminum alloy is placed in to crucible electrical resistance furnace, is warming up to higher than 50~80 DEG C of technical pure aluminum or aluminum alloy fusing points and makes its fusing, after degasification slagging-off is processed, obtain clean fine aluminium or aluminium alloy melt.
(2) continue to be warming up to 750~850 DEG C, by the CuO/Al of aluminium foil parcel
2o
3nano composite powder pushes melt inside with graphite sleeve, turn on agitator simultaneously, and stirring velocity is 500~1000 r/min, churning time is 10~30 min, obtains compounding flux.
(4) high-energy ultrasonic is processed compounding flux, and frequency is 17~20 KHz, and peak power output is 1~2 KW, and the treatment time is 5~30 min.
(5) above-mentioned compounding flux is cooled to 680~720 DEG C, is poured in the metal type dies of 250~300 DEG C of preheatings, the cooling rear demoulding obtains dispersion-strengthened aluminum matrix composite.
Step a(1) described in CuO/Al
2o
3al in nano composite powder
2o
3content is 10wt.%~90 wt.%.
Step a(1) described in soluble copper salt comprise any one or a few in copper sulfate, cupric chloride, cupric nitrate.
Step b(1) described in aluminium alloy can be any one or a few in Al-Si, Al-Cu, Al-Mg, Al-Zn system.
Step b(2) described in CuO/Al
2o
3the add-on of nano composite powder is 0.2wt.%~2.0 wt.% of dispersion-strengthened aluminum matrix composite.
Step b(2) described in CuO/Al
2o
3nano composite powder add mode for add in batches, be divided into 2~5 equal portions.
Compared with prior art, superiority of the present invention is:
(1) adopt sol-gel method to prepare CuO/Al
2o
3nano composite powder, makes nanometer Al
2o
3mix with CuO uniform particles, ensure on the one hand nanometer Al
2o
3the follow-up abundant dispersion of particle enters aluminium alloy melt inside, on the other hand in the time of nanometer CuO and molten aluminium generation thermite reaction, due to Al
2o
3the existence of particle, plays certain " solid diluting effect " to nanometer CuO powder, prevents that reaction process from blasting, and the Cu that thermite reaction generates plays solution strengthening effect, has improved Al simultaneously
2o
3the interface wet ability of particle and aluminum substrate, thus the interface performance of matrix material improved.
(2) utilize graphite sleeve by CuO/Al
2o
3nano composite powder pushes melt inside, has solved the problem that enhanced granule that traditional enhanced granule mode that adds produces floats over bath surface or adheres to smelting pot inwall.
(3), under high-energy ultrasonic effect, the rolling disturbance that simultaneously utilizes violent surface reaction to form, realizes the nanometer Al that surface reaction generates
2o
3particle and CuO/Al
2o
3the nanometer Al that nano composite powder is directly introduced
2o
3the disperse of particle in whole aluminium alloy melt distributes, and strengthening effect further strengthens.
(4) adopt the aluminum matrix composite prepared of the inventive method, there is the performance of high abrasion, high tenacity, have a extensive future.
Embodiment
Embodiment 1
(1) sol-gel method is prepared CuO/Al
2o
3nano composite powder: preparation 0.1 mol/L CuSO
4, 1.4 mol/L NH
4al (SO
4)
2) the aqueous solution as reaction mother liquor, preparation 5.8 mol/L NH
4hCO
3solution, as precipitation agent, adds 500 ml precipitant solution in 500 ml reaction mother liquors, adds 0.5 mol/L NH in reaction system simultaneously
3h
2it is neutral that O regulation system pH value remains, with ultrasonic dispersion 5 min after the lasting stirring of 100 r/min stirring velocitys 10 min, ultrasonic power is 100 W.By after above-mentioned gained water-sol ageing 10 h, remove supernatant liquid, after centrifuge dehydration, obtain gel.After gel being dried at 80 DEG C, pulverize, in 500 DEG C of air, calcine 60 min and obtain CuO/Al
2o
3nano composite powder, wherein Al
2o
3content is 90wt.%.
(2) high-energy ultrasonic legal system is for dispersion-strengthened aluminum matrix composite: 500 g commercial-purity aluminiums are placed in to crucible electrical resistance furnace, are warming up to 710 DEG C and make its fusing, after degasification slagging-off is processed, obtain clean melt.Continue to be warming up to 750 DEG C, by 10 g CuO/Al
2o
3nano composite powder is divided equally 5 parts, after aluminium foil parcel, pushes molten aluminium inside with graphite sleeve, stirs 10 min with 1000 r/min stirring velocitys, obtains clad aluminum melt.Afterwards clad aluminum melt is applied supersound process 30 min of frequency 20 KHz, peak power output 1 KW.Above-mentioned melt is cooled to 680 DEG C, is poured in the metal type dies of 250 DEG C of preheatings, the cooling rear demoulding obtains dispersion-strengthened aluminum matrix composite.
Embodiment 2
(1) sol-gel method is prepared CuO/Al
2o
3nano composite powder: preparation 5.8 mol/L Cu (NO
3)
2, 10 mol/L NH
4al (SO
4)
2) the aqueous solution as reaction mother liquor, preparation 51.6 mol/L NH
4hCO
3solution, as precipitation agent, adds 500 ml precipitant solution in 500 ml reaction mother liquors, adds 1.0 mol/L NH in reaction system simultaneously
3h
2it is neutral that O regulation system pH value remains, with ultrasonic dispersion 30 min after the lasting stirring of 500 r/min stirring velocitys 60 min, ultrasonic power is 1000 W.By after above-mentioned gained water-sol ageing 24 h, remove supernatant liquid, after centrifuge dehydration, obtain gel.After gel being dried at 80 DEG C, pulverize, in 900 DEG C of air, calcine 120 min and obtain CuO/Al
2o
3nano composite powder, wherein Al
2o
3content is 10wt.%.
(2) high-energy ultrasonic legal system is for dispersion-strengthened aluminum matrix composite: 800 g 2024 aluminium alloys are placed in to crucible electrical resistance furnace, are warming up to 750 DEG C and make its fusing, after degasification slagging-off is processed, obtain clean melt.Continue to be warming up to 850 DEG C, by 1.6 g CuO/Al
2o
3nano composite powder is divided equally 2 parts, after aluminium foil parcel, pushes molten aluminium inside with graphite sleeve, stirs 30 min with 500 r/min stirring velocitys, obtains clad aluminum melt.Afterwards clad aluminum melt is applied supersound process 5 min of frequency 17 KHz, peak power output 2 KW.Above-mentioned melt is cooled to 700 DEG C, is poured in the metal type dies of 300 DEG C of preheatings, the cooling rear demoulding obtains dispersion-strengthened aluminum matrix composite.
Embodiment 3
(1) sol-gel method is prepared CuO/Al
2o
3nano composite powder: preparation 3.2 mol/L CuCl
2, 5 mol/L NH
4al (SO
4)
2) the aqueous solution as reaction mother liquor, preparation 26.4 mol/L NH
4hCO
3solution, as precipitation agent, adds 500 ml precipitant solution in 500 ml reaction mother liquors, adds 0.8 mol/L NH in reaction system simultaneously
3h
2it is neutral that O regulation system pH value remains, with ultrasonic dispersion 20 min after the lasting stirring of 300 r/min stirring velocitys 30 min, ultrasonic power is 600 W.By after above-mentioned gained water-sol ageing 18 h, remove supernatant liquid, after centrifuge dehydration, obtain gel.After gel being dried at 80 DEG C, pulverize, in 750 DEG C of air, calcine 90 min and obtain CuO/Al
2o
3nano composite powder, wherein Al
2o
3content is 50wt.%.
(2) high-energy ultrasonic legal system is for dispersion-strengthened aluminum matrix composite: 400 g 6063 aluminium alloys are placed in to crucible electrical resistance furnace, are warming up to 730 DEG C and make its fusing, after degasification slagging-off is processed, obtain clean melt.Continue to be warming up to 800 DEG C, by 4 g CuO/Al
2o
3nano composite powder is divided equally 4 parts, after aluminium foil parcel, pushes molten aluminium inside with graphite sleeve, stirs 20 min with 800 r/min stirring velocitys, obtains clad aluminum melt.Afterwards clad aluminum melt is applied supersound process 15 min of frequency 19 KHz, peak power output 1.5 KW.Above-mentioned melt is cooled to 720 DEG C, is poured in the metal type dies of 300 DEG C of preheatings, the cooling rear demoulding obtains dispersion-strengthened aluminum matrix composite.