CN103469021A - Engine piston aluminum alloy and preparation method thereof - Google Patents

Abstract

The invention discloses an engine piston aluminum alloy and a preparation method thereof. The engine piston aluminum alloy comprises, by mass, 8.5-12.5% of Si, 1.8-2.4% of Cu, 0.6-1.2% of Mg, 1.2-1.6% of Ni, 0.15-0.25% of Zn, 0.1-0.2% of Mn, 0.4-0.8% of Zr, 0.05-0.1% of Cr, 0.03-0.05% of Fe, 0.04-0.08% of Ti, 0.01-0.02% of B, 0.025-0.035% of Li, 0.02-0.03% of In, 0.015-0.025% of Bi, 0.04-0.06% of La, 0.02-0.04% of Tm, and the balance Al. Master alloying elements comprising Si, Cu, Ni, Mg and the like, and micro alloying elements comprising B, Li, In, Bi, La, Tm and the like respectively perform performs, so the alloying effect is realized, the mechanical strength, the wear resistance, the high temperature and dimension stabilities and the like of the alloy are improved, and demands of large-power engine pistons on a highly-mechanical-load and thermal-load piston material are satisfied.

Description

Aluminium alloy and preparation method thereof for a kind of engine piston

Technical field

The present invention relates to aluminium alloy and preparation method thereof for a kind of engine piston, belong to the aluminum alloy materials field.

Background technology

Piston is called as the heart of engine, and it is one of most important part in engine, and its function is to bear gaseous tension, and passes to connecting rod by wrist pin and order about crankshaft rotation.When engine operation, piston directly contacts with the high-temperature gas of 2200 ℃ of transient temperatures, its head temperature reaches 300-400 ℃, and also bearing very large gaseous tension, petrol motor reaches 4-5MPa, diesel engine is up to 8-9MPa, even higher, so piston is bearing thermal load and the mechanical load of high temperature, high pressure.Along with improving constantly of engine power, the performances such as the mechanical property of piston aluminium alloy, thermotolerance, wear resistance are had higher requirement.

Summary of the invention

The object of the present invention is to provide aluminium alloy and preparation method thereof for a kind of engine piston, this alloy heat conductivity is good, and hot strength is high, and wear resistance is good, good stability of the dimension.

The technical solution used in the present invention is as follows:

A kind of engine piston aluminium alloy, its each element consists of by mass percentage: Si 8.5-12.5, Cu 1.8-2.4, Mg 0.6-1.2, Ni 1.2-1.6, Zn 0.15-0.25, Mn 0.1-0.2, Zr 0.4-0.8, Cr 0.05-0.1, Fe 0.03-0.05, Ti 0.04-0.08, B 0.01-0.02, Li 0.025-0.035, In 0.02-0.03, Bi 0.015-0.025, La 0.04-0.06, Tm 0.02-0.04, surplus are aluminium.

The preparation method of aluminium alloy for engine piston: add fine aluminium ingot, magnesium ingot and zinc ingot metal in intermediate frequency furnace, be heated to 710-720 ℃, after all melting, add Al-Si, Al-Cu alloy, be warming up to 730-750 ℃, after all melting clearly, add Al-Mn alloy, Al-Ti-B, Al-Ni alloy, Zr alloy, stir 30-40min, after all melting clearly, temperature adjustment is to 720-740 ℃, add refining agent refining 20-25min, rear standing 10-15min skims; Be cooled to 690-710 ℃, add rare earth alloy ingot and other master alloy, standing 20-30min after all dissolving, be warming up to 720-730 ℃ and shift out crucible, and standing 20-30s, cast after skimming; The ingot casting of gained is warming up to 240-280 ℃ with 110-130 ℃/h speed, insulation 3-6h, then be warming up to 420-450 ℃ with 80-100 ℃/h speed, insulation 2-3h, then be warming up to 510-530 ℃ with 40-50 ℃/h speed, insulation 10-15h; Then be cooled to 340-390 ℃ with 70-90 ℃/h speed, insulation 5-10h, the 40-50 ℃ of water of quenching, be cooled to 180-220 ℃, insulation 3-5h, air cooling to room temperature gets final product;

Described refining agent preparation method is as follows: a. takes the raw material of following weight part: magnesium chloride 10-15, bariumchloride 5-10, potassium sulphide 5-10, vermiculite 8-12, sodium aluminum fluoride 5-10, quartz sand 3-6, bauxitic clay 4-8, water glass 20-30, nano-silicon nitride 5-10, nano silicon carbide calcium 8-12; B. vermiculite, sodium aluminum fluoride, quartz sand, bauxitic clay were pulverized to the 400-500 mesh sieve, mix, add again water glass, nano-silicon nitride, nano silicon carbide calcium and appropriate water, 3000-5000rpm speed lapping 5-10min, granulate, then by the particle that makes at 450-480 ℃ of lower roasting 3-5h, be cooled to room temperature, stand-by; C. magnesium chloride, bariumchloride, potassium sulphide are mixed, be heated to 930-950 ℃, after its whole meltings, the particle that above-mentioned steps (b) is made adds in fused solution and stirs, and pours into bulk, treats that it is cooled to room temperature and is the gained refining agent.

The de-percentage of admixture of refining agent of the present invention between 65-75%, remove the inclusion in aluminium alloy and make inclusion modification effective, purify aluminium alloy and improved internal soundness, degree of porosity reduces the 1-2 degree, is controlled effectively.

 

Beneficial effect of the present invention:

Alloy of the present invention is usingd Si, Cu, Ni, Mg etc. as the master alloying element, B, Li, In, Bi, La, Tm etc. are as micro alloying element, brought into play the effect of each element, realized the alloying effect, improve the performances such as physical strength, wear resistance, high temperature and dimensional stability of alloy, can meet the demand of high-power engine piston to higher mechanical load and thermal load piston material.

Embodiment

a kind of engine piston aluminium alloy, its each element consists of by mass percentage: Si 8.5-12.5, Cu 1.8-2.4, Mg 0.6-1.2, Ni 1.2-1.6, Zn 0.15-0.25, Mn 0.1-0.2, Zr 0.4-0.8, Cr 0.05-0.1, Fe 0.03-0.05, Ti 0.04-0.08, B 0.01-0.02, Li 0.025-0.035, In 0.02-0.03, Bi 0.015-0.025, La 0.04-0.06, Tm 0.02-0.04, surplus are aluminium.

The preparation method of aluminium alloy for engine piston: add fine aluminium ingot, magnesium ingot and zinc ingot metal in intermediate frequency furnace, be heated to 715 ℃, after all melting, add Al-Si, Al-Cu alloy, be warming up to 740 ℃, after all melting clearly, add Al-Mn alloy, Al-Ti-B, Al-Ni alloy, Zr alloy, stir 30min, temperature adjustment to 730 ℃ after all melting clearly, add refining agent refining 20min, rear standing 15min skims; Be cooled to 710 ℃, add rare earth alloy ingot and other master alloy, standing 20min after all dissolving, be warming up to 725 ℃ and shift out crucible, and standing 25s, cast after skimming; The ingot casting of gained is warming up to 260 ℃ with 120 ℃/h speed, insulation 4h, then be warming up to 440 ℃ with 100 ℃/h speed, insulation 2h, then be warming up to 520 ℃ with 40 ℃/h speed, insulation 12h; Then be cooled to 360 ℃ with 80 ℃/h speed, insulation 8h, the 40 ℃ of water of quenching, be cooled to 190 ℃, insulation 4h, air cooling to room temperature gets final product;

Described refining agent preparation method is as follows: a. takes the raw material of following weight (kg): magnesium chloride 10, bariumchloride 10, potassium sulphide 6, vermiculite 8, sodium aluminum fluoride 7, quartz sand 5, bauxitic clay 6, water glass 20, nano-silicon nitride 6, nano silicon carbide calcium 8; B. vermiculite, sodium aluminum fluoride, quartz sand, bauxitic clay were pulverized to 400 mesh sieves, mixed, then added water glass, nano-silicon nitride, nano silicon carbide calcium and appropriate water, 4000rpm speed lapping 6min, granulate, then by the particle that makes at 460 ℃ of lower roasting 4h, be cooled to room temperature, stand-by; C. magnesium chloride, bariumchloride, potassium sulphide are mixed, be heated to 935 ℃, after its whole meltings, the particle that above-mentioned steps (b) is made adds in fused solution and stirs, and pours into bulk, treats that it is cooled to room temperature and is the gained refining agent.

The aluminium alloy made is through check, and its salient features is: tensile strength 386Mpa, yield strength is 262Mpa, thermal conductivity 203W/mk, linear expansivity 14.6 * 10-6 1/K.

Claims (2)

1. an engine piston aluminium alloy, it is characterized in that: its each element consists of by mass percentage: Si 8.5-12.5, Cu 1.8-2.4, Mg 0.6-1.2, Ni 1.2-1.6, Zn 0.15-0.25, Mn 0.1-0.2, Zr 0.4-0.8, Cr 0.05-0.1, Fe 0.03-0.05, Ti 0.04-0.08, B 0.01-0.02, Li 0.025-0.035, In 0.02-0.03, Bi 0.015-0.025, La 0.04-0.06, Tm 0.02-0.04, surplus are aluminium.

2. the preparation method of aluminium alloy for engine piston according to claim 1, it is characterized in that: add fine aluminium ingot, magnesium ingot and zinc ingot metal in intermediate frequency furnace, be heated to 710-720 ℃, after all melting, add Al-Si, Al-Cu alloy, be warming up to 730-750 ℃, after all melting clearly, add Al-Mn alloy, Al-Ti-B, Al-Ni alloy, Zr alloy, stir 30-40min, after all melting clearly, temperature adjustment, to 720-740 ℃, adds refining agent refining 20-25min, and rear standing 10-15min skims; Be cooled to 690-710 ℃, add rare earth alloy ingot and other master alloy, standing 20-30min after all dissolving, be warming up to 720-730 ℃ and shift out crucible, and standing 20-30s, cast after skimming; The ingot casting of gained is warming up to 240-280 ℃ with 110-130 ℃/h speed, insulation 3-6h, then be warming up to 420-450 ℃ with 80-100 ℃/h speed, insulation 2-3h, then be warming up to 510-530 ℃ with 40-50 ℃/h speed, insulation 10-15h; Then be cooled to 340-390 ℃ with 70-90 ℃/h speed, insulation 5-10h, the 40-50 ℃ of water of quenching, be cooled to 180-220 ℃, insulation 3-5h, air cooling to room temperature gets final product;

Described refining agent preparation method is as follows: a. takes the raw material of following weight part: magnesium chloride 10-15, bariumchloride 5-10, potassium sulphide 5-10, vermiculite 8-12, sodium aluminum fluoride 5-10, quartz sand 3-6, bauxitic clay 4-8, water glass 20-30, nano-silicon nitride 5-10, nano silicon carbide calcium 8-12; B. vermiculite, sodium aluminum fluoride, quartz sand, bauxitic clay were pulverized to the 400-500 mesh sieve, mix, add again water glass, nano-silicon nitride, nano silicon carbide calcium and appropriate water, 3000-5000rpm speed lapping 5-10min, granulate, then by the particle that makes at 450-480 ℃ of lower roasting 3-5h, be cooled to room temperature, stand-by; C. magnesium chloride, bariumchloride, potassium sulphide are mixed, be heated to 930-950 ℃, after its whole meltings, the particle that above-mentioned steps (b) is made adds in fused solution and stirs, and pours into bulk, treats that it is cooled to room temperature and is the gained refining agent.