A kind of slurry is coated with the preparation method of surface active ZTA particle enhanced steel iron-based composite wear-resistant part
Technical field
The invention belongs to wearing composite material preparation field, be specifically related to a kind of slurry and be coated with the preparation method of 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 be resisted abrasive action, metallic matrix has given ceramic particle supporting role, and guarantees that composite wear-resistant part entirety has higher obdurability.In addition, different ceramic/metal combinations make wearing piece be applicable to various working conditions, and as high temperature, HI high impact, corrosive environment etc., therefore it has the potentiality that are 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 whole layer 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 that strengthens 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 are good, and 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 is very easily because thermal stress generates crackle, 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
2o
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 ceramics particle prefabricated section, then utilizing technology of infiltration casting is a kind of effective ways of preparation table surface composite material.Wherein time prepared by prefabricated section, metal dust mixes with its mechanical agitation as the binding agent of ceramic particle, after inserting the mould compacting of definite shape, carry out sintering, but powder is difficult to be uniformly distributed at particle surface, can greatly reduces the intensity of prefabricated section and be unfavorable for that the casting of molten metal afterwards blends the homogeneity of whole composite bed performance.
Summary of the invention
The object of the invention is to overcome above technical problem, has proposed a kind of slurry that guarantees that wearing piece has high-wearing feature and longer service life under high stress and be coated with the preparation method of 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 to mixed-powder, wherein multicomponent reactive elemental metalpowder is a kind of or its mixture in Ni, Cr;
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 and in slurry, keep taking out and placing 10-60min after 10-30s, repeat to immerse and be coated with 10~20 times, slurry is coated with and hangs over ZTA particle surface;
4) the ZTA particle after being coated with is inserted after graphite jig is exerted pressure and put into stove sintering, when being warming up to the decomposition temperature of liquid-containing binder with the programming rate of 5-10 ℃/min, room temperature is incubated 20-30min, then after continuing to be warming up to 950-1100 ℃ of sintering temperature, be incubated 1-2 hour, lower the temperature with 4-6 ℃/min subsequently, cooling with stove after being cooled to 900 ℃, ZTA particle is interconnected to form porous preforming piece;
5) porous preforming piece is fixed on to 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 ℃.
The porosity of described porous preforming piece is 50~70%.
Described molten metal is high manganese steel, low-alloy steel, chromium alloy cast iron, nickel system alloy cast iron or the spheroidal graphite cast-iron of manufacturing wearing piece.
Compared with prior art, the present invention has advantage and effect comprise:
The ZTA(Zirconia reinforced alumina using in the present invention) pottery has high rigidity, high-wearing feature, and because the toughening effect of zirconia uniqueness wherein has high tenacity, and can be by regulating thermal coefficient of expansion, hardness and toughness that wherein aluminium oxide changes ZTA from zirconic ratio to mate different metallic matrixes and working condition, alternative conventional pottery, as strengthening particle, has huge application potential.But the poor wetability of ZTA and metal is the difficult problem that needs solve.
In the present invention, utilize Ni, Ti active element powder that ZTA surface is activated, the method that uses slurry to be coated with can guarantee 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 after Infiltration casting process in be present in compound interface and 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, is the effective measures of improving ceramic/metal compound interface performance.
In the present invention, the shape of porous preforming piece, size can be controlled by mould, are applicable to the preparation of variety classes wearing piece.In the wearing piece composite bed preparing, ZTA particulates reinforcements and steel substrate distribute alternately, have pinning effect, and the bond strength of composite bed and matrix is high.In addition, in composite bed, the relatively low metallic matrix of hardness is worn gradually and caves in, and causes reinforcement at one's side to bear main wearing and tearing, to prevent that matrix from further being worn and torn, i.e. and " macroscopical shadow effect ".In reinforcement, also comprise ZTA particle simultaneously and infiltrate the metal two-phase in prefabricated section hole, thereby wherein ZTA particle also can protrude from metal around and resists wearing and tearing, i.e. " microcosmic shadow effect ".Therefore the composite wear-resistant part in the present invention, because above-mentioned " two shadow effect " has high-wearing feature and longer service life, has greatly improved economic benefit.
The specific embodiment
Embodiment 1: grinding roller
1) first, adopt ball mill mixing 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 ℃ 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 and in slurry, keep taking out and placing 10-60min after 10-30s, repeat to immerse and be coated with 10~20 times, slurry is coated with and hangs over ZTA particle surface;
4) the ZTA particle after being coated with is inserted after graphite jig is exerted pressure and put into stove sintering, when being warming up to the decomposition temperature of liquid-containing binder with the programming rate of 5 ℃/min, room temperature is incubated 20-30min, then after continuing to be warming up to 980 ℃ of sintering temperatures, be incubated 1-2 hour, lower the temperature with 4 ℃/min subsequently, cooling with stove after being cooled to 900 ℃, it is 50~70% porous preforming piece that ZTA particle is interconnected to form porosity;
5) porous preforming piece is fixed on to the end face side of rubber-tyred grinding roller mould by the spacing of 15mm, obtains composite grinding roll after adopting negative pressure technology of infiltration casting cast spheroidal graphite cast-iron cooling and demolding.
Embodiment 2: grinder hammerhead
1) active metal element powders Ni is put into liquid-containing binder borax soln, make the dispersed formation slurry of powder at 400 ℃ 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 and in slurry, keep taking out and placing 10-60min after 10-30s, repeat to immerse and be coated with 10~20 times, slurry is coated with and hangs over ZTA particle surface;
3) the ZTA particle after being coated with is inserted after graphite jig is exerted pressure and put into stove sintering, when being warming up to the decomposition temperature of liquid-containing binder with the programming rate of 10 ℃/min, room temperature is incubated 20-30min, then after continuing to be warming up to 1020 ℃ of sintering temperatures, be incubated 1-2 hour, lower the temperature with 6 ℃/min subsequently, cooling with stove after being cooled to 900 ℃, it is 50~70% porous preforming piece that ZTA particle is interconnected to form porosity;
4) porous preforming piece is fixed on to 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 metal element powders Cr is put into liquid-containing binder aluminum phosphate solution, make the dispersed formation slurry of powder at 200 ℃ 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 and in slurry, keep taking out and placing 10-60min after 10-30s, repeat to immerse and be coated with 10~20 times, slurry is coated with and hangs over ZTA particle surface;
3) the ZTA particle after being coated with is inserted after graphite jig is exerted pressure and put into stove sintering, when being warming up to the decomposition temperature of liquid-containing binder with the programming rate of 9 ℃/min, room temperature is incubated 20-30min, then after continuing to be warming up to 950 ℃ of sintering temperatures, be incubated 1-2 hour, lower the temperature with 5 ℃/min subsequently, cooling with stove after being cooled to 900 ℃, it is 50~70% porous preforming piece that ZTA particle is interconnected to form porosity;
4) multiple prefabricated sections are fixed on to the end face side of broken machine bar mould.While preparing the bar of thinner thickness, can put into the row's precast body that is elongated strip; While preparing thicker large bar, can put into many row's precast bodies, between each precast body, at a distance of 25mm, adopt common technology of infiltration casting cast rich chromium cast iron, after cooling and demolding, obtain composite wear-resistant part.