A kind of slurry is coated with the preparation method that ZTA strengthens steel-based composite wear-resistant part
Technical field
The invention belongs to wearing composite material preparation field, be specifically related to the preparation method that a kind of slurry is coated with surface active ZTA particle enhanced steel iron-based composite wear-resistant part.
Background technology
Ceramic particle reinforced metal base composites has had the characteristic of two-phase concurrently, wherein the ceramic particle of high strength, high rigidity can resist abrasive action, metallic matrix then gives ceramic particle supporting role, and ensures that composite wear-resistant part entirety has higher obdurability.In addition, different ceramic/metal combinations makes wearing piece be applicable to various working condition, and as high temperature, HI high impact, corrosive environment etc., therefore it has the potentiality be widely used in harsh wear working condition.Especially top layer composite abrasion resistance material, can greatly improve the toughness of wearing piece and reduce costs.Traditional flood surface recombination wearing piece easily peels off at thump, heavily stressed lower composite bed, shortens the service life of wearing piece, even causes serious accident.
The performance strengthening particle in ceramic particle reinforced metal base composites is one of key factor determining its wearability.Conventional enhancing pottery is carbide, oxide etc.Wherein WC and iron liquid wetting good, compound interface place can form firmly metallurgical binding, but the linear expansion coefficient of itself and iron and steel is widely different, make its thermal shock resistance very poor, compound interface place very easily generates crackle because of thermal stress, and WC is expensive, brings very high production cost.Another conventional enhancing pottery Al
2o
3price lower, better with the thermal matching of iron and steel, but Al
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3very high intrinsic fragility particle is easily fractureed under effect of stress, have a strong impact on the wearability of composite, and Al
2o
3very poor with the wetability of iron and steel, the difficulty of preparation high-performance composite wear-resistant part is larger.
In existing preparation method, first adopt sintering process to prepare porous ceramic particles prefabricated section, then utilize technology of infiltration casting to be a kind of effective ways of preparation table surface composite material.Wherein when prepared by prefabricated section, metal dust mixes with its mechanical agitation as the binding agent of ceramic particle, sinter after inserting the mould compacting of definite shape, but powder is difficult to be uniformly distributed at particle surface, can greatly reduce prefabricated section intensity and after being unfavorable for the casting of molten metal blend the homogeneity of whole composite bed performance.
Summary of the invention
The object of the invention is to overcome above technical problem, proposes the preparation method that a kind of slurry ensureing that wearing piece has high-wearing feature and longer service life under high stress is coated with surface active ZTA particle enhanced steel iron-based composite wear-resistant part.
For achieving the above object, the preparation method that the present invention adopts comprises the following steps:
1) first, multicomponent reactive elemental metalpowder and absolute ethyl alcohol wet mixing are obtained mixed-powder, wherein multicomponent reactive elemental metalpowder is one in Ni, Cr or its mixture;
2) above-mentioned mixed-powder is put into liquid-containing binder, utilize constant temperature blender with magnetic force to make the dispersed formation slurry of powder, in slurry, the content of active element powder is 100-500g/L;
3) 10-20 object ZTA particle is put into screen cloth, and immerse in slurry keep 10-30s after take out place 10-60min, repeat immersion and be coated with 10 ~ 20 times, slurry be coated with hang over ZTA particle surface;
4) the ZTA particle after being coated with is inserted put into stove after graphite jig is exerted pressure and sinter, 20-30min is incubated when room temperature is warming up to the decomposition temperature of liquid-containing binder with the programming rate of 5-10 DEG C/min, then 1-2 hour is incubated after continuing to be warming up to 950-1100 DEG C of sintering temperature, lower the temperature with 4-6 DEG C/min subsequently, with stove cooling after being cooled to 900 DEG C, ZTA particle is interconnected to form porous preforming block;
5) porous preforming block is fixed on the end face side of casting mold by the spacing of 15-30mm, adopts technology of infiltration casting casting of molten metal, after cooling and demolding, obtain composite wear-resistant part.
Described wet mixing adopts ball milling or mixing machine batch mixing.
Described liquid-containing binder is hydroxypropyl methylcellulose, polyethylene glycol, 1-Methoxy-2-propyl acetate, borax soln, aluminum phosphate or Phosphoric Acid-Copper Oxide.
The temperature that described temperature constant magnetic stirring forms slurry is 150-400 DEG C.
The porosity of described porous preforming block is 50 ~ 70%.
Described molten metal is manufacture the high manganese steel of wearing piece, low-alloy steel, chromium alloy cast iron, nickel system alloy cast iron or spheroidal graphite cast-iron.
Compared with prior art, the advantage that has of the present invention and effect comprise:
ZTA (Zirconia reinforced alumina) pottery used in the present invention has high rigidity, high-wearing feature, and because of wherein zirconia uniqueness toughening effect and there is high tenacity, and by regulating wherein aluminium oxide and zirconic ratio to change the thermal coefficient of expansion of ZTA, hardness and toughness to mate different metallic matrixes and working condition, alternative conventional pottery, as strengthening particle, has huge application potential.But ZTA and the poor wetability of metal are the difficult problems needing to solve.
Ni, Ti active element powder is utilized to be activated on ZTA surface in the present invention, the method using slurry to be coated with can ensure that active element powder wraps up covering completely ZTA particle equably, at high temperature form complete sintering shell, give the intensity that prefabricated section is higher, and in Infiltration casting process afterwards, be present in compound interface sentence and avoid ZTA to contact with the direct of steel substrate.Active element and ZTA and matrix phase counterdiffusion, form metallurgical binding, can greatly improve interface wet ability and bond strength, be the effective measures improving ceramic/metal compound interface performance.
In the present invention, the shape of porous preforming block, size control by mould, are applicable to the preparation of variety classes wearing piece.In the wearing piece composite bed prepared, ZTA particulates reinforcements and steel substrate distribute alternately, have pinning effect, and the bond strength of composite bed and matrix is high.In addition, the metallic matrix that in composite bed, hardness is relatively low is worn gradually and caves in, and causes reinforcement at one's side to bear key wear, to prevent matrix from being worn and torn further, i.e. " macroscopical shadow effect ".Also the metal two-phase comprising ZTA particle simultaneously and infiltrate in prefabricated section hole in reinforcement, wherein ZTA particle also can protrude from the metal of surrounding thus resist wearing and tearing, i.e. " microcosmic shadow effect ".Therefore the composite wear-resistant part in the present invention has high-wearing feature and longer service life due to above-mentioned " two shadow effect ", greatly improves economic benefit.
Detailed description of the invention
Embodiment 1: grinding roller
1) first, ball mill mixing is adopted to obtain mixed-powder in the mixture of multicomponent reactive elemental metalpowder Ni and Cr and absolute ethyl alcohol;
2) above-mentioned mixed-powder is put into liquid-containing binder hydroxypropyl methylcellulose, make the dispersed formation slurry of powder at 300 DEG C of temperature constant magnetic stirrings, in slurry, the content of active element powder is 300g/L;
3) 10-20 object ZTA particle is put into screen cloth, and immerse in slurry keep 10-30s after take out place 10-60min, repeat immersion and be coated with 10 ~ 20 times, slurry be coated with hang over ZTA particle surface;
4) the ZTA particle after being coated with is inserted put into stove after graphite jig is exerted pressure and sinter, 20-30min is incubated when room temperature is warming up to the decomposition temperature of liquid-containing binder with the programming rate of 5 DEG C/min, then 1-2 hour is incubated after continuing to be warming up to 980 DEG C of sintering temperatures, lower the temperature with 4 DEG C/min subsequently, with stove cooling after being cooled to 900 DEG C, ZTA particle is interconnected to form the porous preforming block that porosity is 50 ~ 70%;
5) porous preforming block is fixed on the end face side of rubber-tyred grinding roller mould by the spacing of 15mm, after adopting negative pressure technology of infiltration casting cast spheroidal graphite cast-iron cooling and demolding, obtains composite grinding roll.
Embodiment 2: grinder hammerhead
1) active metallic element powder Ni is put into liquid-containing binder borax soln, make the dispersed formation slurry of powder at 400 DEG C of temperature constant magnetic stirrings, in slurry, the content of active element powder is 500g/L;
2) 10-20 object ZTA particle is put into screen cloth, and immerse in slurry keep 10-30s after take out place 10-60min, repeat immersion and be coated with 10 ~ 20 times, slurry be coated with hang over ZTA particle surface;
3) the ZTA particle after being coated with is inserted put into stove after graphite jig is exerted pressure and sinter, 20-30min is incubated when room temperature is warming up to the decomposition temperature of liquid-containing binder with the programming rate of 10 DEG C/min, then 1-2 hour is incubated after continuing to be warming up to 1020 DEG C of sintering temperatures, lower the temperature with 6 DEG C/min subsequently, with stove cooling after being cooled to 900 DEG C, ZTA particle is interconnected to form the porous preforming block that porosity is 50 ~ 70%;
4) porous preforming block is fixed on the end face side of grinder hammerhead mould by the spacing of 30mm, adopts centrifugal casting cementation process cast high manganese steel, after cooling and demolding, obtain composite wear-resistant part.
Embodiment 3: plate hammer for crusher
1) active metallic element powder cr is put into liquid-containing binder aluminum phosphate solution, make the dispersed formation slurry of powder at 200 DEG C of temperature constant magnetic stirrings, in slurry, the content of active element powder is 100g/L;
2) 10-20 object ZTA particle is put into screen cloth, and immerse in slurry keep 10-30s after take out place 10-60min, repeat immersion and be coated with 10 ~ 20 times, slurry be coated with hang over ZTA particle surface;
3) the ZTA particle after being coated with is inserted put into stove after graphite jig is exerted pressure and sinter, 20-30min is incubated when room temperature is warming up to the decomposition temperature of liquid-containing binder with the programming rate of 9 DEG C/min, then 1-2 hour is incubated after continuing to be warming up to 950 DEG C of sintering temperatures, lower the temperature with 5 DEG C/min subsequently, with stove cooling after being cooled to 900 DEG C, ZTA particle is interconnected to form the porous preforming block that porosity is 50 ~ 70%;
4) multiple prefabricated section is fixed on the end face side of broken machine bar mould.The row's precast body in elongated strip can be put into when preparing the bar of thinner thickness; Can put into when preparing thicker large bar and arrange precast body more, at a distance of 25mm between each precast body, adopt common technology of infiltration casting to pour into a mould rich chromium cast iron, after cooling and demolding, obtain composite wear-resistant part.