Summary of the invention
The alloy for hot-dip that the object of the present invention is to provide a kind of titanium alloy component surface coating to use, even the contact corrosion resistant coating that adopts this alloy for hot-dip preparation is under the effect of rugged environment and stress, can not peel off yet, and the performance of contact corrosion resistant also is improved greatly, thereby has thoroughly solved the crevice corrosion problem of titanium alloy and aluminium alloy and ferrous materials.
The alloy for hot-dip that is exclusively used in titanium alloy component surface coating provided by the invention, wherein said alloy for hot-dip is made up of aluminium, silicon, zinc, rare earth element, iron and nano-oxide particles toughener, the per-cent that each composition accounts for total mass is: silicone content: 8~24%, zinc content: 1.2~3.1%, the content of rare earth element: 0.02~0.5%, iron level: 0.05~1%, the total content of nano-oxide particles toughener: 1~2%, surplus is aluminium and unavoidable impurities, and described nano-oxide particles toughener is selected from TiO
2, CeO
2In one or both.
Preferably, if the nano-oxide toughener particle that adopts is uniform spherical particles, then spheroid specific surface area and median size satisfy following relational expression:
Wherein D represents median size;
ρ represents density.
If the nano-oxide toughener particle that adopts is more complex-shaped than general spherical particles, the performance of coating, effect can be desirable more, and therefore, the specific surface area of the further preferred nano-oxide toughener of the present invention is greater than above-mentioned formula calculated value:
Preferably, nano-oxide particles adopts TiO
2The time, described TiO
2Median size be 15~60nm.
Preferably, nano-oxide particles adopts TiO
2The time, described TiO
2Specific surface area be 20~90m
2/ g.
Preferably, nano-oxide particles adopts CeO
2The time, described CeO
2Median size be 25~70nm.
Preferably, nano-oxide particles adopts CeO
2The time, described CeO
2Specific surface area be 10~80m
2/ g.
Preferably, the nano-oxide particles toughener is TiO
2And CeO
2The time, TiO
2And CeO
2Mass ratio is 1: (1~3).
Preferred, TiO wherein
2And CeO
2Mass ratio is 1: 2.
Preferably, wherein each composition accounts for total mass per-cent and is: silicone content: 12~20%, and zinc content: 1.5~2.5%, the content of rare earth element: 0.1~0.3%, iron level: 0.2~0.8%, the total content of nano-oxide particles toughener: 1.2~1.8%.
In addition; the present invention also provides a kind of method of making described alloy for hot-dip; according to aluminium; silicon; zinc; rare earth element; the mass percent of iron and nano-oxide particles toughener is got the raw materials ready; earlier in the atmosphere protection smelting furnace; aluminum silicon alloy is heated to 750~800 ℃ of fully fusings earlier; add rare earth element after being warming up to 845~855 ℃ again; stir; reheat adds zinc after being warming up to 860~880 ℃; add nano-oxide particles toughener and iron more simultaneously through being cooled to 750~700 ℃; through machinery; electromagnetism is compound to stir, and temperature is reduced to that 700~650 ℃ of insulations obtained in 20~30 minutes again.
Wherein, the temperature rise rate in the described heat-processed is 10~40 ℃/minute, and the rate of temperature fall in the described temperature-fall period is 20~60 ℃/minute.
The aluminium silicon coating that the present invention adopts is to prevent that titanium alloy from corroding effective coating of particularly high temperature corrosion, and wherein aluminium mainly provides corrosive nature and the persistent corrosion resistance under the high-temperature condition; And silicon can further improve abrasion property, elevated temperature corrosion resistant improves.
Yet, raising along with silicone content, the toughness of coating descends to some extent, be unfavorable for load, the synergistic crevice corrosion of medium, for this reason, the present invention is by adding the nano-oxide particles toughener, refinement the crystal grain of coating, significantly improve its toughness, significantly improved the contact corrosion resistant ability simultaneously.In addition, also significantly improve coating opposing atomospheric corrosion, galvanic corrosion and airflow scouring erosive ability, and significantly improved intensity, the hardness of coating, thereby given coating better scour resistance.
Further, after testing repeatedly in a large number, screening,, can improve the contact corrosion resistant ability of coating more significantly by selecting the particle diameter and the specific surface area of suitable nano-oxide particles toughener.In addition, the particle diameter of nano-oxide particles toughener adopts numerical range of the present invention, the fastness to rubbing of coating is improved greatly, and the specific surface area of nano-oxide particles toughener adopts numerical range of the present invention, the concentration class of alloy is improved greatly, thereby improve the scour resistance of alloy coat more significantly.
In addition, the zinc that further adds in the coating provides extraordinary galvanic protection, rare earth then further refinement the crystallization crystal grain of alloy, and strengthened the wear resistance and the liquid fluidity of alloy.
On this basis, further add microalloy elements such as iron, the adding of these microalloy elements is crystal grain thinning more, and strengthened the strengthening phase in the coating, also alloy has been played the solid solution effect, and further improved the toughness and the stability of coating, further improved the obdurability and the erosion resistance of coating.In addition, iron can also play and improve oxidation resistant effect.
On the other hand, the present invention also provides a kind of method that adopts many temperature sections to add the alloy for hot-dip element, adopt this method, raising along with temperature, can help improving the dispersiveness of nano-oxide particles toughener and various elements, thereby improved the homogeneity of coated component, improved coating and high base strength significantly.
Yet if add all elements when melt temperature is too high, coating easily forms high alumina fragility phase, is unfavorable for bearing contact fine motion load.For this reason, the present invention adopts earlier many temperature sections to add part alloy for hot-dip elements, adds the nano-oxide particles toughener again after temperature being reduced to certain temperature again, lower the temperature again at last and be incubated certain hour, so just overcome above-mentioned defective, it is even to have obtained composition, and toughness is coating preferably.
In sum, the present invention is by to the improvement of alloy and melting technology thereof, can titanium alloy surface form anti-corrosion, wear resistance good, the coating that gets togather with the matrix metallurgical junction.Materials such as coating current potential and aluminium alloy are approaching, can prevent the crevice corrosion of aeronautical materials such as titanium alloy component and aluminium alloy, superalloy.Even the contact corrosion resistant coating that adopts this alloy for hot-dip preparation is under the effect of rugged environment and stress, can not peel off yet, and the performance of contact corrosion resistant also is improved greatly, thereby thoroughly solved the crevice corrosion problem of titanium alloy and aluminium alloy and ferrous materials, to the application of further expansion titanium alloy at aviation field, the lifting that promotes aeroplane performance has great importance.
Embodiment
The alloy for hot-dip that is exclusively used in titanium alloy component surface coating of the present invention, wherein said alloy for hot-dip is made up of aluminium, silicon, zinc, rare earth element, iron and nano-oxide particles toughener, the per-cent that each composition accounts for total mass is: silicone content: 8~24%, zinc content: 1.2~3.1%, the content of rare earth element: 0.02~0.5%, iron level: 0.05~1%, the total content of nano-oxide particles toughener: 1~2%, surplus is aluminium and unavoidable impurities, and described nano-oxide particles toughener is selected from TiO
2, CeO
2In one or both, this impurity that can not the avoid impurity element that can't thoroughly remove such as Pb, Sn, Cd normally wherein.
Further, after testing repeatedly in a large number, screening, by selecting the particle diameter and the specific surface area of suitable nano-oxide particles toughener, can improve the performance of coating more significantly, if the nano-oxide particles that adopts is uniform spherical particles, then spheroid specific surface area and median size satisfy following relational expression:
Wherein D represents median size;
ρ represents density.
Further, if the nano-oxide particles that adopts is more complex-shaped than general spherical particles, the performance of coating, effect can be desirable more, and therefore, the specific surface area of the preferred nano-oxide particles of the present invention is greater than this formula calculated value.
Preferably, nano-oxide particles adopts TiO
2The time, described TiO
2Median size be 15~60nm.
Preferably, nano-oxide particles adopts TiO
2The time, described TiO
2Specific surface area be 20~90m
2/ g.
Preferably, nano-oxide particles adopts CeO
2The time, described CeO
2Median size be 25~70nm.
Preferably, nano-oxide particles adopts CeO
2The time, described CeO
2Specific surface area be 10~80m
2/ g.
Provide some preferred embodiments of each composition mass percent of the present invention below in conjunction with table 1-3, but the content of each composition of the present invention is not limited to listed numerical value in this table, for a person skilled in the art, fully can be in table rationally summarize and reasoning on the basis of listed numerical range.
And of particular note, although listed file names with the particle diameter of nano-oxide particles, the correlation values of specific surface area among the table 1-3, these two conditions are described as prerequisite.For the present invention, the content of core is by adding crystal grain that certain amount of nano oxide particle toughener reaches the refinement coating, improve its toughness, improve its contact corrosion resistant ability, overcoming the too high dysgenic purpose of bringing of silicone content.And on this basis, by the suitable particle diameter of further selection, suitable specific surface area all is in order to make this technique effect more outstanding, more superior, therefore, although these two parameters that all list file names with among the following table 1-3, but all be preferred condition, all be in order providing in more detail, and described as prerequisite of the present invention about technical intelligence of the present invention.
Embodiment 1:
Described alloy for hot-dip is by aluminium, silicon, zinc, iron, rare earth element and TiO
2The nano-oxide particles toughener is formed, and the per-cent that each composition accounts for total mass is: silicone content: 8~24%, and zinc content: 1.2~3.1%, the content of rare earth element: 0.02~0.5%, iron level: 0.05~1%, TiO
2Content: 1~2%, surplus is an aluminium, concrete sees the following form 1:
Table 1: each composition accounts for the mass percentage content (%) and the index of correlation parameter of gross weight
Embodiment 2:
Described alloy for hot-dip is by aluminium, silicon, zinc, iron, rare earth element and CeO
2The nano-oxide particles toughener is formed, and the per-cent that each composition accounts for total mass is: silicone content: 8~24%, and zinc content: 1.2~3.1%, the content of rare earth element: 0.02~0.5%, iron level: 0.05~1%, CeO
2Content: 1~2%, surplus is an aluminium, concrete sees the following form 2:
Table 2: each composition accounts for the mass percentage content (%) and the index of correlation parameter of gross weight
Embodiment 3:
Described alloy for hot-dip is made up of aluminium, silicon, zinc, iron, rare earth element and nano-oxide particles toughener, and wherein nano-oxide particles is TiO
2And CeO
2, and TiO
2And CeO
2Ratio is 1: the per-cent that (1~3), each composition account for total mass is: silicone content: 8~24%, and zinc content: 1.2~3.1%, the content of rare earth element: 0.02~0.5%, iron level: 0.05~1%, TiO
2And CeO
2Total content: 1~2%, surplus is an aluminium, concrete sees the following form 3:
Table 3: each composition accounts for the mass percentage content (%) and the index of correlation parameter of gross weight
Among the embodiment 1-3, preferred, wherein each composition accounts for total mass per-cent and is: silicone content: 12~20%, zinc content: 1.5~2.5%, the content of rare earth element: 0.1~0.3%, iron level: 0.2~0.8%, the total content of nano-oxide particles toughener: 1.2~1.8%
Preferred, wherein said silicone content is preferred 15~20%, and more preferably 19%.
In addition, find also that if the loose density of the nano-oxide particles toughener that the present invention is adopted also can suitably be selected, the then final coating performance that obtains, effect are with even more ideal by a large amount of experiments repeatedly.
If adopt TiO
2, then preferred, wherein said TiO
2Loose density be no more than 3g/cm
3
If adopt CeO
2, then preferred, wherein said CeO
2Loose density be no more than 5g/cm
3
If adopt TiO simultaneously
2And CeO
2, then preferred, wherein said TiO
2And CeO
2Average loose density is 0.6~4.5g/cm
3
In addition; the present invention also provides a kind of method of making described alloy for hot-dip; according to aluminium; silicon; zinc; rare earth element; the mass percent of iron and nano-oxide particles toughener is got the raw materials ready; earlier in the atmosphere protection smelting furnace; aluminum silicon alloy is heated to 750~800 ℃ of fully fusings earlier; add rare earth element after being warming up to 845~855 ℃ again; stir; reheat adds zinc after being warming up to 860~880 ℃; add nano-oxide particles toughener and iron more simultaneously through being cooled to 750~700 ℃; through machinery; electromagnetism is compound to stir, and temperature is reduced to that 700~650 ℃ of insulations obtained in 20~30 minutes again.
Preferably; mass percent according to aluminium, silicon, zinc, rare earth element, iron and nano-oxide particles toughener is got the raw materials ready; earlier in the atmosphere protection smelting furnace; aluminum silicon alloy is heated to 780~800 ℃ of fully fusings earlier; add rare earth element after being warming up to 850~855 ℃ again; stir; reheat adds zinc after being warming up to 870~880 ℃; add nano-oxide particles toughener and iron more simultaneously through being cooled to 730~700 ℃; through machinery, electromagnetism is compound stirs, and temperature is reduced to that 680~650 ℃ of insulations obtained in 20~25 minutes again.
Preferably, add nano-oxide particles toughener and iron more simultaneously through being cooled to 720~700 ℃; At last temperature is reduced to that 690~660 ℃ of insulations obtained in 22~28 minutes.
Preferred, add nano-oxide particles toughener and iron more simultaneously through being cooled to 710 ℃; Last again temperature is reduced to that 680 ℃ of insulations obtained in 25 minutes.
Temperature rise rate in the wherein said heat-processed is 10~40 ℃/minute, and the rate of temperature fall in the described temperature-fall period is 20~60 ℃/minute.
Preferably, the temperature rise rate in the wherein said heat-processed is 20~30 ℃/minute, and the rate of temperature fall in the described temperature-fall period is 30~50 ℃/minute.
Preferred, the temperature rise rate in the wherein said heat-processed is 25 ℃/minute, and the rate of temperature fall in the described temperature-fall period is 40 ℃/minute.
Bending process and erosion resistance experimental result
Embodiment 4:
The Ti6Al4V bolt, after treatment, adopt alloy for hot-dip of the present invention as coating material, form 300 μ m thick coatings, contact with aluminum alloy part, with reference to air standard HB5374, in 3%NaCl solution, carry out the standard galvanizing corrosion test, average galvanic couple current density is 0.74, reaches the anticorrosive standard of B level, and flawless occurs in the coating.
And adopt conventional coating material, only promptly produce significant corrosion after the several months.
Embodiment 5:
The TA6 part, after treatment, adopt alloy for hot-dip of the present invention as coating material, form 200 μ m thick coatings, contact with the GH30 part, with reference to air standard HB5374, in 3%NaCl solution, carry out the standard galvanizing corrosion test, average galvanic couple current density is 0.27, reaches the anticorrosive standard of A level, and flawless occurs in the coating.
And adopt conventional coating material, only promptly produce significant corrosion after the several months.
In sum, the present invention is by the improvement of coating material, plating technic, can titanium alloy surface form anti-corrosion, wear resistance good, the coating that gets togather with the matrix metallurgical junction.The improvement of any adaptation of carrying out on basis of the present invention does not all break away from thought of the present invention, all falls into the scope of protection of the invention.