PL179730B1 - Multiple-component high-silicon aluminium alloy - Google Patents

Abstract

Multi-component silumin containing in mass percent 2-27% Si, 0.10-5.00% Cu, 0.10-4.00% Ni, up to 1.50% Fe, up to 1.00% Mn, up to 0.40% Ti, up to 4.00% Zn, up to 0.60% Cr, up to 1.20% Co, to 0.20% Sn, 0.10-2.00% Mg and Al, characterized in that it contains in percent mass, 0.01-2.00% V, 0.01-2.00% W, up to 2.00% Mo, up to 1.50% Nb, and the rest is Al.

Description

The subject of the invention is multi-component silumin intended, in particular, for pistons of internal combustion engines.

Known neighborilumines containing in percentages by weight: 4.00-23.00% Si, 0.20-1.50% Mg, 0.20-5.00% Cu, 0.20-1.30% Ni, 0.20 -2.00% Zn, up to 1.50% Fe, up to 0.80% Mn, up to 0.20% Ti, up to 0.10% Sn, up to 0.30% Pb.

The periodicals "MetałłowedenijeiTermiczeskajaObrabotkaMetałłow", No. 7,1993, p. 11 are known silumines composed of: Si-Al-Cu, Si-Al-Mg-Zn, Si-Al-Zn-Mg-Cu, in which the Si content is equal to 2, 00-3.00%.

From W. Hufoagel's book "Key to Aluminum Alloys" 4th Edition. Aluminum Verlag and from catalogs of Nural, Kolben-Schmidt, Mahle companies are known silumines containing in percentages by weight: 7.50-27.00% Si, 0.10-1.50% Mg, 0.10-5.00% Cu, 0.10-4.0% Ni, up to 1.50% Fe, up to 1.00% Mn, up to 0.40% Ti, up to 0.60% Zn, up to 0.20% Sn, up to 0.60% Cr, up to 1.20% Co.

Mechanical properties of known silumin, such as immediate tensile strength (R _m ), yield point (Rp0.2), elongation (A ₅ ), hardness (HB), fatigue strength for two-sided bending (Z _g0 ), fatigue strength for double-sided tensile strength (Z _ro ) are not higher than: R _n <450 MPa, Rp0, ₂ <450 MPa, A ₅ <10%, hardness <130 HB, Zg ₀ <140 x (2 x 10 ⁷ cycles) MPa, Zro <120 x (2 x 10 ⁷ cycles) MPa, the hysteresis of the coefficient of linear thermal expansion Αα ³⁵ 0 50 is much higher than 0, moreover, the mechanical properties of these silumin significantly decrease at elevated temperatures: at 200 ° C by 20-30% and at 350 ° C by as much as 90%.

The silumin according to the invention contains in percentages by mass: 2.00-27.00% Si, 0.10-2.00% Mg, 0.10-5.00% Cu, 0.10-4.00% Ni, up to 1 , 50% Fe, up to 1.00% Mn, up to 0.40% Ti, up to 4.00% Zn, up to 0.60% Cr, up to 1.20% Co, up to 0.20% Sn, 0.01 -2.00% V, 0.01-2.00% W, up to 2% Mo, up to 1.0% Nb with the rest Al.

W, V, Mo and Nb are introduced with the charge or after the charge is melted, preferably in the form of Al-W, Al-V, Al-Mo, Al-Nb, Al-WV alloys or Al-W-Ti-B, Al alloys -V-Ti-B, Al-MoTi-B, Al-Nb-Ti-B, Al-WV-Ti-B.

The silumin according to the invention is poured into sand molds or molds by known methods. It is preferable to modify the silumin according to the invention with known modifiers such as sodium or its salts, strontium, antimony, phosphorus or its compounds, titanium, boron, refining with nitrogen, argon, chlorine or a mixture thereof, and subjecting to precipitation hardening by supersaturation in water at a temperature of 500-540 ° C for 4-6 hours and subsequent aging at 180-240 ° C for 4-12 hours.

The silumin according to the invention is characterized by much better mechanical properties compared to the known silumin, and by the hysteresis of the linear thermal expansion coefficient close to zero. Moreover, its mechanical properties decrease at elevated temperatures to a much lesser extent than those of known silumin. Table 1 compares the mechanical properties, the coefficient of linear thermal expansion and the hysteresis of this coefficient, in the raw state and after heat treatment, as well as the degree of deterioration of the mechanical properties at elevated temperatures of the known silumin and the silumin according to the invention.

Table 1

Property The known silumins The silumin according to the invention temporary tensile strength R _m [MPa] 140-450 250-600 proof stress Rp0.2 [MPa] 80-450 120-460 elongation A, [%] 0.5-10 0.5-10 hardness HB 50-130 70-150 fatigue strength for double bending Z _g0 [MPa] (70-140) x (2 x 10 ⁷ cycles) (90-200) x (2 x 107 cycles) two-sided tensile fatigue strength Zg, [MPa] (50-120) x (2 x, 107 cycles) (70-180) x (2 x 107 cycles) coefficient of linear thermal expansion α / Νο [1 / ° C] (10-24) x 10 ⁶ (12-22) x 106 hysteresis of the linear thermal expansion coefficient AcdNo [1 / ° C] 6.00-0.00) x 10 ⁶ 2.00-0.00) x 106 degree of deterioration of mechanical properties at temperatures: [%] 200 ° C by 20-30% by 3-5% 250 ° C by 50-60% by 10-20% 300 ° C by 70-80% by 30-40% 350 ° by 90% by 50-60%

The following examples illustrate the subject matter of the invention.

Example I.

Silumin with the composition in percent by mass: 10.34% Si, 1.05% Mg, 2.18% Cu, 0.93% Ni, 0.47% Fe, 0.03% Mn, 0.80% V, 1 , 17% W, 0.25% Mo, 0.18% Nb was smelted in an induction furnace, then modified with strontium and refined with a mixture of argon and chlorine. The liquid silumin prepared in this way was poured into a die, the gating system of which was equipped with a filter mesh. The produced cast was 12 mm thick. Properties of the obtained raw silumin at ambient temperature and elevated temperatures are presented in Table 2.

Table 2

Property / temperature surroundings 200 ° C 350 ° C R _m [MPa] 265 260 135 R> p0.2 [MPa] 172 169 83 A5 [%] 1.0 2.0 6.0 hardness HB 95 80 60 With _g0 [MPa] 101 x (2x 107 cycles) 99 x (2 x 107 cycles) 49 x (2 x 10 ⁷ cycles) From _ro [MPa] 85 x (2 x 107 cycles) 83 x (2 x 10 ⁷ cycles) 40 x (2 x 10 'cycles) α ^35θ 5ο [1 / ° C] (20.01-21.54) x 106 Δα ³⁵ 0 ₅ 0 [1 / ° C] (1.92-0.00) x 106

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The obtained silumin was then subjected to precipitation hardening consisting in supersaturation at 520 ° C in water at a temperature of 60 ° C for 4 hours and then cooling in air. The properties of silumin after precipitation hardening at ambient temperature and elevated temperatures are given in Table 3.

Table 3

Property / temperature surroundings 200 ° C 350 ° C R _m [MPa] 430 425 180 Rpo, 2 [MPa] 360 345 180 a ₅ [%] 1.5 2.0 6.5 hardness HB 128 118 68 Z _so [MPa] 126 x (2x 10 ⁷ cycles) 120 x (2 x 107 cycles) 61 x (2 x 107 cycles) From _ro [MPa] 85 x (2 x 107 _C yks) 81 x (2 x 107 cycles) 40 x (2 x 107 cycles) αθθ [1 / ° C] (19.25-20.01) x 10 ⁶ ΔΛ [1 / ° C] (0.91-0.00) x 10 ⁶

Example II.

Silumin with the composition in percent by mass: 18.68% Si, 1.23% Mg, 1.36% Cu, 1.28% Ni, 0.42% Fe, 0.04% Mn, 1.26% V, 0 , 75% W, 1, θ5% Mo, 0.25% Nb was smelted in an induction furnace, then modified with phosphorus and refined with a mixture of argon and chlorine. The silumin prepared in this way was poured into a die, the gating system of which contained a filter mesh. The resulting cast was 12 mm thick. Properties of the obtained raw silumin at ambient temperature and elevated temperatures are presented in Table 4.

Table 4

Property / temperature surroundings 200 ° C 350 ° C R _m [MPa] 238 225 117 Rp0.2 [MPa] 238 225 117 A ₅ [%] 0.1 0.5 3.5 hardness HB 98 89 56 Zgo [MPa] 118 x (2x 107 cycles) 112 x (2 x 10 ⁷ cycles) 56 x (2 x 10 ^? Cycles) Z _ra [MPa] 102 x (2 x 107 cycles) 97 x (2 x 107 cycles) 50 x (2 x 10 ⁷ cycles) ct ³⁵ ° 50 [1 / ° C] (15.00-16.89) x 10 ⁶ Δα ³⁵⁰ 50 [1 / ° C] (1.28-0.00) x 10 ⁶

The produced silumin was subjected to precipitation hardening by supersaturation at 520 ° C in water at 60 ° C for 4 hours, followed by aging at 220 ° C for 4 hours and cooling in air at ambient temperature. The properties of silumin after precipitation hardening at ambient temperature and elevated temperatures are given in Table 5.

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Table 5

Property / temperature surroundings 200 ° C 350 ° C R ". | MPaj 421 408 108 Rpo, 2 [MPa] 421 408 108 A ₅ [%] 0.5 1.0 4.5 hardness HB 139 133 65 With _g0 [MPa] 133 x (2 x 10 ⁷ cycles) 127 x (2 x 107 cycles) 63 x (2 x 107 cycles) From _ro [MPa] 112 x (2 x 107 cycles) 107 x (2 x 107 cycles) 52 x (2 x 10 ⁷ cycles) α ⁵ ° 5o [1 / ° C] (14.52-14.95) x 10 ⁶ Δα ³⁵ ^ [U ° C] (0.06-0.00) x 10 ⁶

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Publishing Department of the UP RP. Circulation of 60 copies

Price PLN 2.00.

Claims (1)

Patent claim Multi-component silumin with mass percentages of 2-27% Si, 0.10-5.00% Cu, 0.10-4.00% Ni, up to 1.50% Fe, up to 1.00% Mn, up to 0.40 % Ti, up to 4.00% Zn, up to 0.60% Cr, up to 1: 20% Co, up to 0.20% Sn, 0.10-2.00% Mg and Al, characterized in that it contains percent by weight, 0.01-20) 0% V, 0.01-2.00% W, up to 2.00% Mo, up to 1.50% Nb) with the balance being Al.