A kind of method for preparing the SiC superfine powder
Technical field
The present invention relates to a kind of method of using high-energy ball milling to prepare the SiC superfine powder, belong to the ceramic preparing technical field.
Background technology
Silit is a kind of strong covalent bond compound; Compare with other material; Silit has excellent mechanical property (high firmness, HS, high-wearing feature, strong creep resistance etc.) and chemicalstability (high temperature resistant, corrosion-resistant, radiation hardness etc.), and thermal conductivity height, the coefficient of expansion are little, also have the excellent photoelectric performance; Therefore, obtained using widely in aerospace, machinery, metallurgy, the energy, environmental protection, chemical industry, medical science, electronics and field such as sophisticated technology such as height such as military project grade.
At present, preparation SiC powder method has a lot, like microwave method, carbon reduction method, polymkeric substance thermal decomposition method, sol-gel method, gas-phase reaction sedimentation, plasma method and mechanical crushing method etc.Sol-gel method is a kind of wet chemistry method for preparing nanoparticle; Ultimate principle is that the chemical reagent with liquid is mixed with metal inorganic salt or metal alkoxide precursor; Precursor is dissolved in and forms uniform solution in the solvent; Solute and solvent form colloidal sol after producing hydrolysis or alcoholysis, and colloidal sol can transfer gel to after long-time placement or drying.Generally contain a large amount of liquid phases in the gel, need remove liquid medium, and thermal treatment forms the particulate of respective substance compound under far below the conventional sintering temperature through extraction or evaporation.Colloidal sol transfers gel to and needs long time in this method, and the production cycle is oversize, unsuitable large-scale industrial production.Mechanical crushing method is to pulverize through stirrer or vibration mill etc., because the extreme hardness of SiC material, the minimum limit of size that makes ball milling SiC material is 0.6~0.7 μ m normally.The ball milling grain diameter more hour, the agglomeration between the particle will be serious more, thereby reduced the ball milling effect.Yet the SiC powder that chemical relatively legal system is equipped with, the SiC powder footpath distribution range of existing mechanical comminuting method preparation is wide, is difficult for guaranteeing the stability and the consistence of quality product.Therefore how using mechanical process to prepare the SiC superfine powder becomes a difficult problem that needs to be resolved hurrily, needs badly and develop grinding process efficiently.
In CN 102020471A patent, having reported a kind of method for preparing silit, is that SiC powder and nano SiC granule are prepared burden by mass ratio, places the water ball milling 8~12 hours, at last with mixed slurry 60 ℃~80 ℃ oven dry in baking oven.The raw material that this method is used is complicated, and operation is more, and cost is high, and wet-grinding technology and relative device need be dried, and energy expenditure is bigger.
In CN 1636870A patent, having reported a kind of method for preparing silit, is that Si source, carbon source and alcohol are mixed by mass ratio, carries out high temperature cabonization processing and high temperature sintering then and handles.The raw material that this method is used is complicated, complex process, and need to handle 1~12 hour at 600 ℃~1000 ℃ high temperature cabonizations, to handle 0.5~8 hour at 1200 ℃~2000 ℃ high temperature sinterings, this has increased the input of cost greatly, has prolonged the cycle of experiment simultaneously.
Summary of the invention
The present invention provides a kind of method of the SiC of preparation superfine powder, and this method technology is simple, cost is low, efficient is high and diameter of particle is evenly distributed.
Technical scheme of the present invention is to be raw material with the SiC powder directly, adopts the method for high-energy ball milling to prepare the SiC superfine powder.Concrete grammar passes through as follows: by ball material mass ratio is that 5:1~40:1 takes by weighing Stainless Steel Ball and SiC powder; And take by weighing the technology controlling and process agent of certain mass; Powder, technology controlling and process agent and steel ball are packed in the horizontal agitating ball mill of high energy, feed shielding gas, according to 200 rev/mins~1000 rev/mins of drum'ss speed of rotation; Ball milling 1~10 hour promptly obtains the SiC superfine powder.
The median size D of said SiC powder
50Be 5 μ m~115 μ m.
The diameter of said Stainless Steel Ball is 1mm~5mm.
Said technology controlling and process agent is Triple Pressed Stearic Acid and polyoxyethylene glycol, and the Triple Pressed Stearic Acid add-on is 0.1%~5.0wt% of SiC powder, and the add-on of polyoxyethylene glycol is 0.1~3.0wt% of SiC powder.
The shielding gas that charges in the said mechanical milling process is argon gas or nitrogen.
Advantage of the present invention and positively effect are:
(1) overcome that the traditional mechanical disintegrating process is complicated, efficient is low, the diameter of particle distribution range is wide, classification is difficult, be difficult for guaranteeing the stability and the conforming shortcoming of quality product, prepared the superfine powder of particle diameter at 0.35~0.55 μ m.
(2) the technology controlling and process agent can better disperse and refinement powder in the high-energy ball milling process, can prevent the reunion of powder, and the size-grade distribution of superfine powder is more even, purity is higher.
(3) suitability for industrialized production, technology is simple, efficient is high, constant product quality and with low cost.
Embodiment
Below in conjunction with embodiment the present invention is done to further describe, but the invention is not restricted to the following stated scope.
Embodiment 1: present embodiment prepares the concrete steps of SiC superfine powder to be passed through as follows:
At first taking by weighing SiC powder and the diameter that median size is 5 μ m~115 μ m according to ball material mass ratio 5:1 is the 5mm Stainless Steel Ball; Take by weighing 1.0wt% Triple Pressed Stearic Acid and 0.5wt% polyoxyethylene glycol again; Powder, technology controlling and process agent and steel ball are packed in the horizontal agitating ball mill of high energy, charge into argon shield.It is that 600 rev/mins, ball milling time are 4h that the ball milling parameter of ball mill is set to rotational speed of ball-mill.After ball milling finishes, take by weighing the SiC powder behind a small amount of ball milling, add ethanol and be mixed with dilute suspension, record the median size D of submicron order SiC
50Be 0.50 μ m.
Embodiment 2: present embodiment prepares the concrete steps of SiC superfine powder to be passed through as follows:
At first taking by weighing SiC powder and the diameter that median size is 5~115 μ m according to ball material mass ratio 30:1 is the Stainless Steel Ball of 3mm; Take by weighing 5wt% Triple Pressed Stearic Acid and 3wt% polyoxyethylene glycol again; Powder, technology controlling and process agent and steel ball are packed in the horizontal agitating ball mill of high energy, charge into nitrogen protection.It is that 200 rev/mins, ball milling time are 10h that the ball milling parameter of ball mill is set to rotational speed of ball-mill.After ball milling finishes, take by weighing the SiC powder behind a small amount of ball milling, add water and be mixed with dilute suspension, record the median size D of submicron order SiC
50Be 0.39 μ m.
Embodiment 3: present embodiment prepares the concrete steps of SiC superfine powder to be passed through as follows:
At first taking by weighing SiC powder and the diameter that median size is 5~115 μ m according to ball material mass ratio 40:1 is the Stainless Steel Ball of 1mm; Take by weighing 0.1wt% Triple Pressed Stearic Acid and 0.1wt% polyoxyethylene glycol again; Powder, technology controlling and process agent and steel ball are packed in the horizontal agitating ball mill of high energy, charge into nitrogen protection.It is that 1000 rev/mins, ball milling time are 1h that the ball milling parameter of ball mill is set to rotational speed of ball-mill.After ball milling finishes, take by weighing the SiC powder behind a small amount of ball milling, add water and be mixed with dilute suspension, record the median size D of submicron order SiC
50Be 0.42 μ m.