CN103924132A - Preparation method of high corrosion resistant and high wear resistant aluminium alloy profile for engine cylinder cover - Google Patents

Abstract

The invention discloses a preparation method of a high corrosion resistant and high wear resistant aluminium alloy profile for an engine cylinder cover. the aluminium alloy profile is composed of the following elements, by weight, 9.4-10.8% of Si, 0.7-1.4% of Cu, 0.4-0.8% of Mg, 0.15-0.25% of Fe, 0.3-0.6% of Cr, 0.05-0.1% of Mn, 0.02-0.04% of Zn, 0.01-0.02% of Ni, 0.03-0.05% of As, 0.025-0.045% of Sn, 0.02-0.03% of Cd, 0.015-0.025% of Hf, 0.005-0.01% of B, 0.02-0.04% of Ce, 0.01-0.03% of Yb and the balance Al. The aluminium alloy profile prepared by the above method has excellent comprehensive properties and high high-temperature strength, can operate at 250-300 DEG C for a long time, has excellent corrosion resistance and wear resistance, and has a wide application prospect.

Description

A kind of preparation method of high corrosion-resistance wear-resistance engine cylinder cover aluminium alloy extrusions

Technical field

The preparation method who the present invention relates to a kind of high corrosion-resistance wear-resistance engine cylinder cover aluminium alloy extrusions, belongs to aluminum alloy materials processing technique field.

Background technology

Engine is the heart of automobile, and cylinder head is a strength member on engine, its complex structure, and camshaft is contact running with it directly, and aluminum alloy materials wear resistance will be got well, and the high temperature that cylinder cap and cylinder body junction surface will resistance to 240 ℃ of left and right.Meanwhile, also will stand the corrosion of sulfur oxide and dilute sulphuric acid that water vapour forms in oil inflame after product, working conditions is severe.Therefore strict especially to the aluminum alloy materials performance requriements of production cylinder head, not only require hot strength high, good toughness, also requires to have good wear resistance and erosion resistance.

Summary of the invention

Object of the present invention is providing a kind of preparation method of high corrosion-resistance wear-resistance engine cylinder cover aluminium alloy extrusions.This aluminium alloy extrusions excellent combination property, hot strength is high, and good toughness has good wear resistance and erosion resistance.

For achieving the above object, the technical solution used in the present invention is as follows:

A preparation method for high corrosion-resistance wear-resistance engine cylinder cover aluminium alloy extrusions, comprises the following steps:

(1) by aluminium ingot, magnesium ingot, aluminium scrap drops into smelting furnace and carries out melting, smelting temperature 730-750 ℃, and until it molten clear 80% when above, input Al-Si, the master alloys such as Al-Cu, after it all melts, adjust temperature to 740-760 ℃, add the hexachloroethane of melt weight 0.2-0.3% and the Sodium tetrafluoroborate refining 15-20min of 0.15-0.25%, induction stirring 10-15min after refining, standing 20-30min, then adjusts temperature to 755-775 ℃, adds Al-Ti-B-Ce master alloy, insulation 5-10min, skim, sampling analysis, the weight percent of strictly controlling each elemental composition of aluminium alloy solution meets the following requirements: Si 9.4-10.8, Cu 0.7-1.4, Mg 0.4-0.8, Fe 0.15-0.25, Cr 0.3-0.6, Mn 0.05-0.1, Zn 0.02-0.04, Ni 0.01-0.02, As 0.03-0.05, Sn 0.025-0.045, Cd 0.02-0.03, Hf 0.015-0.025, B 0.005-0.01, Ce 0.02-0.04, Yb 0.01-0.03, surplus is Al,

(2) adopt semicontinuous direct water-cooling castmethod to cast, casting temp is 720-740 ℃, casting speed 70-90mm/min, and cooling water pressure 0.15-0.25MPa, cooling water flow is 1600-1800 L/min;

(3) aluminium alloy cast ingot is carried out to homogenizing processing: first with 150-200 ℃/h, be warming up to 350-400 ℃, insulation 3-6h, with 80-120 ℃/h, be cooled to 160-220 ℃ again, insulation 1-2h, then with 100-150 ℃/h, be warming up to 420-460 ℃, insulation 4-8h, then strong wind cooling is to 220-250 ℃, insulation 2-3h, with 120-160 ℃/h, be warming up to 480-510 ℃ again, insulation 5-10h, then water smoke is cooled to 150-200 ℃, insulation 1-2h, with 100-150 ℃/h, be warming up to 400-450 ℃ again, insulation 4-6h, then with 120-160 ℃/h, be cooled to 140-180 ℃, insulation 1-2h, air cooling is to room temperature,

(4) ingot casting after above-mentioned homogenizing processing is heated to 465-495 ℃, then puts into the mould extrusion machine extrusion molding that is preheated to 470-500 ℃, extruding rate is 10-15m/min, and mold clearing temperature is 510-530 ℃;

(5) the aluminium alloy extrusions water smoke of above-mentioned extrusion molding is cooled to 200-250 ℃, then with 80-120 ℃/h, be warming up to 450-490 ℃, insulation 3-5h, then be cooled to 240-280 ℃/h with 100-150 ℃/h, insulation 2-3h, then puts into 0-5 ℃ of icy salt solution and is cooled to below 50 ℃;

(6) aluminium alloy extrusions is carried out to ageing treatment: first with 45-55 ℃/h, be warming up to 90-110 ℃, insulation 10-15h, with 50-60 ℃/h, be warming up to 190-210 ℃ again, insulation 5-10h, with 60-70 ℃/h, be cooled to 65-75 ℃ again, insulation 15-20h, air cooling is to room temperature, then with 40-50 ℃/h, be warming up to 80-90 ℃, insulation 12-16h, air cooling is to room temperature, then with 75-85 ℃/h, be warming up to 150-170 ℃, insulation 8-12h, air cooling is to room temperature, then with 80-90 ℃/h, be warming up to 175-195 ℃, insulation 5-10h, with 40-50 ℃/h, be cooled to 85-95 ℃ again, insulation 10-15h, air cooling is to room temperature.

Beneficial effect of the present invention:

The present invention rationally adjusts the content of Si element, suitably improve the content of Cu, Mg element, solution strengthening and second-phase by aluminum substrate are strengthened, the intensity of alloy is improved, and high-temperature behavior is improved, and adds micro-Ce, Yb rare earth element simultaneously, can crystal grain thinning, improve as-cast structure, also can improve corrosion resistance nature, make aluminium alloy extrusions more durable in use.Aluminium alloy extrusions excellent combination property prepared by the inventive method, hot strength is high, can long term operation at 250-300 ℃ of temperature, and there is good erosion resistance and wear resistance, have a extensive future.

Embodiment

a preparation method for high corrosion-resistance wear-resistance engine cylinder cover aluminium alloy extrusions, comprises the following steps:

(1) by aluminium ingot, magnesium ingot, aluminium scrap drops into smelting furnace and carries out melting, 740 ℃ of smelting temperatures, until it molten clear 80% when above, drop into Al-Si, the master alloys such as Al-Cu, after it all melts, adjust temperature to 750 ℃, add the hexachloroethane of melt weight 0.2% and 0.2% Sodium tetrafluoroborate refining 20min, induction stirring 15min after refining, standing 30min, then adjust temperature to 765 ℃, add Al-Ti-B-Ce master alloy, insulation 7min, skim, sampling analysis, the strict weight percent of controlling each elemental composition of aluminium alloy solution meets the following requirements: Si 9.4-10.8, Cu 0.7-1.4, Mg 0.4-0.8, Fe 0.15-0.25, Cr 0.3-0.6, Mn 0.05-0.1, Zn 0.02-0.04, Ni 0.01-0.02, As 0.03-0.05, Sn 0.025-0.045, Cd 0.02-0.03, Hf 0.015-0.025, B 0.005-0.01, Ce 0.02-0.04, Yb 0.01-0.03, surplus is Al,

(2) adopt semicontinuous direct water-cooling castmethod to cast, casting temp is 730 ℃, casting speed 80mm/min, and cooling water pressure 0.2MPa, cooling water flow is 1700 L/min;

(3) aluminium alloy cast ingot is carried out to homogenizing processing: first with 180 ℃/h, be warming up to 360 ℃, insulation 5h, then be cooled to 180 ℃ with 100 ℃/h, insulation 1h, is then warming up to 460 ℃ with 150 ℃/h, insulation 4h, then strong wind cooling to 240 ℃, is incubated 2h, then is warming up to 510 ℃ with 140 ℃/h, insulation 6h, then water smoke is cooled to 200 ℃, insulation 2h, with 120 ℃/h, be warming up to 440 ℃ again, insulation 4h, is then cooled to 150 ℃ with 150 ℃/h, insulation 1h, air cooling is to room temperature;

(4) ingot casting after above-mentioned homogenizing processing is heated to 485 ℃, then puts into the mould extrusion machine extrusion molding that is preheated to 500 ℃, extruding rate is 12m/min, and mold clearing temperature is 520 ℃;

(5) the aluminium alloy extrusions water smoke of above-mentioned extrusion molding is cooled to 230 ℃, then with 100 ℃/h, is warming up to 470 ℃, insulation 4h, then be cooled to 260 ℃/h with 120 ℃/h, insulation 2h, then puts into 2 ℃ of icy salt solutions and is cooled to below 50 ℃;

(6) aluminium alloy extrusions is carried out to ageing treatment: first with 50 ℃/h, be warming up to 105 ℃, insulation 12h, then be warming up to 210 ℃ with 60 ℃/h, insulation 5h, then with 70 ℃/h, be cooled to 70 ℃, insulation 15h, air cooling, to room temperature, is then warming up to 90 ℃ with 45 ℃/h, insulation 12h, air cooling, to room temperature, is then warming up to 160 ℃ with 80 ℃/h, insulation 10h, air cooling, to room temperature, is then warming up to 180 ℃ with 90 ℃/h, insulation 7h, with 45 ℃/h, be cooled to 95 ℃ again, insulation 10h, air cooling is to room temperature.

Through check, the above-mentioned aluminium alloy extrusions chemical composition making is: Si 10.26%, Cu 1.25%, Mg 0.72%, Fe 0.19%, Cr 0.48%, Mn 0.084%, Zn 0.036%, Ni 0.014%, As 0.048%, Sn 0.037%, Cd 0.023%, Hf 0.022%, B 0.0064%, Ce 0.039%, Yb 0.021%, and surplus is Al; The mechanical property of this aluminium alloy extrusions in the time of 300 ℃ is: tensile strength 284MPa, yield strength 208MPa, elongation 10.7%.

Claims (1)

1. a preparation method for high corrosion-resistance wear-resistance engine cylinder cover aluminium alloy extrusions, is characterized in that comprising the following steps:

(1) by aluminium ingot, magnesium ingot, aluminium scrap drops into smelting furnace and carries out melting, smelting temperature 730-750 ℃, and until it molten clear 80% when above, input Al-Si, the master alloys such as Al-Cu, after it all melts, adjust temperature to 740-760 ℃, add the hexachloroethane of melt weight 0.2-0.3% and the Sodium tetrafluoroborate refining 15-20min of 0.15-0.25%, induction stirring 10-15min after refining, standing 20-30min, then adjusts temperature to 755-775 ℃, adds Al-Ti-B-Ce master alloy, insulation 5-10min, skim, sampling analysis, the weight percent of strictly controlling each elemental composition of aluminium alloy solution meets the following requirements: Si 9.4-10.8, Cu 0.7-1.4, Mg 0.4-0.8, Fe 0.15-0.25, Cr 0.3-0.6, Mn 0.05-0.1, Zn 0.02-0.04, Ni 0.01-0.02, As 0.03-0.05, Sn 0.025-0.045, Cd 0.02-0.03, Hf 0.015-0.025, B 0.005-0.01, Ce 0.02-0.04, Yb 0.01-0.03, surplus is Al,

(2) adopt semicontinuous direct water-cooling castmethod to cast, casting temp is 720-740 ℃, casting speed 70-90mm/min, and cooling water pressure 0.15-0.25MPa, cooling water flow is 1600-1800 L/min;

(3) aluminium alloy cast ingot is carried out to homogenizing processing: first with 150-200 ℃/h, be warming up to 350-400 ℃, insulation 3-6h, with 80-120 ℃/h, be cooled to 160-220 ℃ again, insulation 1-2h, then with 100-150 ℃/h, be warming up to 420-460 ℃, insulation 4-8h, then strong wind cooling is to 220-250 ℃, insulation 2-3h, with 120-160 ℃/h, be warming up to 480-510 ℃ again, insulation 5-10h, then water smoke is cooled to 150-200 ℃, insulation 1-2h, with 100-150 ℃/h, be warming up to 400-450 ℃ again, insulation 4-6h, then with 120-160 ℃/h, be cooled to 140-180 ℃, insulation 1-2h, air cooling is to room temperature,

(4) ingot casting after above-mentioned homogenizing processing is heated to 465-495 ℃, then puts into the mould extrusion machine extrusion molding that is preheated to 470-500 ℃, extruding rate is 10-15m/min, and mold clearing temperature is 510-530 ℃;

(5) the aluminium alloy extrusions water smoke of above-mentioned extrusion molding is cooled to 200-250 ℃, then with 80-120 ℃/h, be warming up to 450-490 ℃, insulation 3-5h, then be cooled to 240-280 ℃/h with 100-150 ℃/h, insulation 2-3h, then puts into 0-5 ℃ of icy salt solution and is cooled to below 50 ℃;

(6) aluminium alloy extrusions is carried out to ageing treatment: first with 45-55 ℃/h, be warming up to 90-110 ℃, insulation 10-15h, with 50-60 ℃/h, be warming up to 190-210 ℃ again, insulation 5-10h, with 60-70 ℃/h, be cooled to 65-75 ℃ again, insulation 15-20h, air cooling is to room temperature, then with 40-50 ℃/h, be warming up to 80-90 ℃, insulation 12-16h, air cooling is to room temperature, then with 75-85 ℃/h, be warming up to 150-170 ℃, insulation 8-12h, air cooling is to room temperature, then with 80-90 ℃/h, be warming up to 175-195 ℃, insulation 5-10h, with 40-50 ℃/h, be cooled to 85-95 ℃ again, insulation 10-15h, air cooling is to room temperature.