The mechanical preparation method of nano ceramics and micron metal composite granule
Technical field
The present invention relates to a kind of preparation method of new material, especially a kind of preparation method of micro-nano composite, the mechanical preparation method of specifically a kind of nano ceramics and micron metal composite granule.
Background technology
Along with the development of nanosecond science and technology, the emphasis of nano materials research has been turned to the applicating and exploitation of nano block and nano coating gradually by single nano powder preparation, and it is one of them important development trend that nano-ceramic particle strengthens metal-base composites.As everyone knows, after size reached nanometer scale, the surface of single nano particle can be very high, surface-active is very big, very unstable, very easily adsorb other materials or particle, attract each other between them and reunite, make that the practical effect of nano-powder is relatively poor, its many excellent specific property forfeitures.Lot of domestic and foreign studies show that if nano powder and powder and micron are carried out suitable compound tense, the composite granule that makes often all can show nano-meter characteristic to some extent, also can present compound collaborative multifunctional effect simultaneously.Therefore, the preparation of nano ceramics and micron metal composite granule becomes one of hot issue of engineering research.
Micro-nano composite granule preparation method generally can be divided into four big classes such as Mechanical Method, vapor phase method, liquid phase method and solid phase method.Wherein, control advantages such as continuous batch production easily, in production practices, obtained using widely but Mechanical Method has course of reaction.The proportioning of nano-powder and micro-powder and the adding technology of nano-powder are the core technologies in nano ceramics and the micron metal composite granule preparation mechanical technology, also are the deciding factors of decision composite granule serviceability.
About the proportion relation of nano-powder and micro-powder, the existing research test method(s)s that adopt more, this method exists bigger blindness, usually needs to test repeatedly just to draw proportion relation preferably.Simultaneously, because the otherness and the diversity of the rerum natura of little, nano-powder, existing research does not have directive function substantially to different powders.Japan scholar M.Alonso etc. has proposed a kind of nano particle and the micro particles quantitative proportion model with the cladded type compound tense, but nano particle is to exist to be coated on the micro particles surface and to form two kinds of forms of microaggregate in nano ceramics and micron metal machinery composite granule, and be main existence form with the latter in most cases, this model and nano ceramics and the compound actual conditions of micron metal powder machinery differ bigger.Therefore, the accurate estimation of nano ceramics and micron metal powder machinery compound tense powder proportion relation or definite blank that still is in.
About the adding technology of nano-powder, existing research mostly is directly and nano powder and powder and micron is mixed to carry out machinery compound.But in fact itself just there has been more soft-agglomerated even hard aggregation in nano-powder in the process that preparation is collected, do not mixed with powder and micron if do not handle directly, the energy that is provided in the machinery recombination process can't be broken reunion (its SEM shape appearance figure as shown in Figure 1), and single powder characteristic will be had a greatly reduced quality even be lower than to the performance of Zhi Bei nano ceramics and micron metal composite granule thus.The domestic scholar of having has proposed as adding dispersant at little, nanometer mixed powder or micro-powder and nano-powder being made suspension respectively mix and carry out methods such as machinery is compound.Wherein, the former is better than the composite granule effect that does not add dispersant, and in fact role is very limited but directly add dispersant; The latter requires micro-powder and nano-powder are all made suspension, and in fact can't make suspension for most micron order metal-powders, so these methods all exist significant limitation.
Therefore, up to the present, do not obtain as yet a kind of with the marketization nano-ceramic powder and the micron metal powder as raw material, the mechanical preparation method for preparing micro-nano composite granule conscientiously, simply, efficiently can be for promoting and engineering is used.
Summary of the invention
The objective of the invention is at the limitation of existing micro-nano composite granule preparation existence big, do not take into full account the two quality proportioning and cause the big problem of preparation difficulty, invent a kind of market-oriented nano-ceramic powder and micron metal powder of adopting as raw material, by mechanical composite algorithm, conscientiously simple and effective ground prepares micro-nano composite granule, thereby effectively improves the nano-ceramic powder of the marketization and result of use and the nano ceramics of added value and the mechanical preparation method of micron metal composite granule of micron metal powder.
Technical scheme of the present invention is:
The mechanical preparation method of a kind of nano ceramics and micron metal composite granule is characterized in that:
At first calculate both quality proportionings,, then carry out the quality proportioning by following formula if both particle diameters differ 3 orders of magnitude or 3 more than the order of magnitude according to the particle diameter of selected nano-ceramic powder and micron metal powder:
Wherein:
ε
Wt: the quality proportioning of nano-ceramic powder and micron metal powder;
g
n: the density of nano-ceramic powder material;
g
w: the density of micron metal powder body material;
Otherwise, carry out the quality proportioning by following formula:
Wherein: D: the average grain diameter of micron metal powder;
D: the average grain diameter of nano-ceramic powder;
Secondly, nano-ceramic powder is made uniform and stable nano ceramics suspension;
The 3rd, to meet the micron metal powder of first step gained quality proportion relation and the nano ceramics suspension of the second step gained, putting into mechanical equipment complex together, to carry out machinery compound, through behind 30~60 minutes mechanical compound, it is carried out drying can obtain compound uniform nano ceramics and micron metal composite granule.
Described mechanical equipment complex is a ball mill.
Beneficial effect of the present invention:
(1) the inventive method has characteristics such as technology is simple, the processing time is extremely short, course of reaction is controlled easily, the production of energy continuous batch, nano ceramics and micron metal composite granule be can prepare conscientiously, simply, efficiently, the market-oriented nano-powder and the result of use and the added value of micro-powder improved effectively.
(2) the inventive method adopts theoretical model to set up nano-ceramic powder and the comparatively accurate proportion relation of micron metal powder, has avoided the blindness of test method(s), has shortened the test searching process, has very strong engineering using value.
(3) the inventive method directly adopts nano suspending liquid as the powder machinery complex media, has solved the nano ceramics and the relatively poor problem of the actual serviceability of micron metal composite granule that cause owing to the already present reunion of nano-powder itself effectively.
(4) the present invention has provided the theoretical model of nano-ceramic powder and micron metal powder proportion relation by a large amount of tests.Disclosed theoretical model is applicable to the nano-ceramic powder of heterogeneity and determining of micron metal powder proportion relation; Simultaneously, simple clear and definite, the acquisition easily of the meaning of this model desired parameters can be used for instructing actual engineer operation.
(5) theoretical model that the inventive method disclosed, when the particle diameter of nano-powder and micro-powder differs 3 orders of magnitude or 3 orders of magnitude when above, this model is only relevant with powder body material density, has reduced the general error that distributes and cause greatly of diameter of particle, and determined proportion relation is more accurate.
(6) nano particle is uniformly dispersed in the nano suspending liquid that the inventive method adopted, and the mechanical compound required time of little, nano-powder is extremely short, has very high efficient.
Description of drawings
Fig. 1 be not treated nano-powder directly with after micro-powder mixes, carry out SEM (scanning electron display device) shape appearance figure of mechanical compound prepared micro-nano composite granule.
Fig. 2 adopts method of the present invention to prepare the SEM shape appearance figure of the micro-nano composite granule of gained.
The specific embodiment
The present invention is further illustrated below in conjunction with drawings and Examples.
The mechanical preparation method of a kind of nano ceramics and micron metal composite granule, it is made up of following steps.
At first, calculate the quality proportioning of nano-ceramic powder and micron metal powder according to theoretical model.Wherein, when the particle diameter of nano-ceramic powder and micron metal powder differs 1-2 the order of magnitude (less than 3 orders of magnitude), adopt formula 2 to carry out the quality proportioning and calculate; When the particle diameter of nano-powder and micro-powder differs 3 orders of magnitude or 3 orders of magnitude when above, adopt formula 1 to carry out the quality proportioning and calculate:
Wherein:
ε
Wt: the quality proportioning of nano-ceramic powder and micron metal powder;
g
n: the density of nano-ceramic powder material;
g
w: the density of micron metal powder body material;
D: the average grain diameter of micron metal powder;
D: the average grain diameter of nano-ceramic powder;
Secondly, in liquid medium (as absolute ethyl alcohol), adopts ultrasonic wave to disperse the nano-ceramic powder or the dispersion of employing emulsification cutter after, leave standstill and made uniform and stable nano suspending liquid in 60 minutes.
The 3rd, according to the good proportion relation of aforementioned calculation, putting into ball mill after an amount of micron metal powder and nano ceramics suspension mixed, to carry out machinery compound, after mechanical compound 30~60 minutes, is dried and can obtains nano ceramics and micron metal composite granule.
Below be according to method of the present invention prepared nano ceramics and micron metal composite granule example, but be not limited only to these examples, for the nano-ceramic powder and the micron metal powder of heterogeneity,, all can reach purpose of the present invention as long as adopt the method for the invention.
Example 1: selecting commercial average grain diameter for use is the pure aluminium powder of 6 μ m and the SiC powder that average grain diameter is 25nm, and the density of micro-powder material is 2.7g/cm
3, the density of nano-powder material is 3.2g/cm
3The particle diameter of nano-powder and micro-powder differs 2 orders of magnitude in this example, and therefore adopting formula 2 to calculate its quality proportioning is 4: 100.After the nano SiC powder put into absolute ethyl alcohol and adopt the emulsification cutter to disperse, leave standstill made uniform and stable nano suspending liquid in 60 minutes after, to mix by nano SiC suspension that calculates good proportioning weighing and micron pure aluminium powder, it is compound to adopt wet ball grinding to carry out powder machinery then, ball milling speed is 150r/min, the ball milling time is 60 minutes, and ratio of grinding media to material 3: 1 can be prepared nano ceramics and micron metal composite granule that nano particle is evenly distributed.
Example 2: selecting commercial average grain diameter for use is that the equal particle diameter of NiCrAlY powder peace of 75 μ m is the Al of 20nm
2O
3Powder, the density of micro-powder material are 8.5g/cm
3, the density of nano-powder material is 3.97g/cm
3Because the particle diameter of nano-powder and micro-powder differs 3 orders of magnitude in this example, adopt formula 1 to calculate its quality proportioning, the quality proportioning that can get nano-ceramic powder and micron metal powder is 1.2: 100.With nanometer Al
2O
3Powder is put into absolute ethyl alcohol and is adopted ultrasonic wave to disperse after 30 minutes, leave standstill made uniform and stable nano suspending liquid in 60 minutes after, will be by the nanometer Al that calculates good proportioning weighing
2O
3Suspension and micron NiCrAlY powder mix, it is compound to adopt wet ball grinding to carry out powder machinery then, and ball milling speed is 260r/min, and the ball milling time is 30 minutes, ratio of grinding media to material 3: 1 can be prepared nano ceramics and micron metal composite granule that nano particle is evenly distributed.The SEM shape appearance figure of gained composite granule as shown in Figure 2.Can find out significantly that from the contrast of Fig. 2 and Fig. 1 the structural homogeneity of the two has difference in essence.Can find out thus the present invention by controlling two kinds of powders the quality proportioning and improve the preparation method and promptly earlier nano-powder made nano suspending liquid to carry out machinery with micro-powder then compound, the composite granule of preparation can not only show nano-meter characteristic well, also can present compound collaborative multifunctional effect simultaneously.