Heat-resistant regeneration die-cast aluminum alloy and preparation method thereof

Abstract

The invention discloses a heat-resistant regeneration die-cast aluminum alloy and a preparation method thereof, and belongs to the field of regeneration die-cast aluminum alloy preparation. The invention provides the heat-resistant regeneration die-cast aluminum alloy capable of reducing the preparation cost and the preparation method of the heat-resistant regeneration die-cast aluminum alloy. Chemical components of the heat-resistant regeneration die-cast aluminum alloy include 10.0%-12.0% of Si, 0.50%-0.75% of Ni, 0.95%-1.35% of Mg, 0.9%-1.4% of Fe, 0.20%-0.30% of Mn, 0.08%-0.12% of Cr, 0.015%-0.03% of B, smaller than or equal to 0.15% of an impurity element and the balance Al. The preparation method includes the steps that smelting is conducted; sampling is conducted to adjust the alloycomponents; refining is conducted after low-melting-point alloy addition; slag removal is conducted; and casting is conducted. According to the heat-resistant regeneration die-cast aluminum alloy andthe preparation method, Ni and Cu are replaced with the low-cost impurity element Fe, and the alloy cost is effectively reduced; and by means of the compound modification technology of the Mn, the Cr, the B and the like, the size of the iron-rich phase is refined, and the high-temperature strength of the alloy is ensured.

Description

technical field [0001] The invention relates to the field of preparation of recycled die-casting aluminum alloys, in particular to a heat-resistant recycled die-casting aluminum alloy and a preparation method thereof. Background technique [0002] Al-Si cast aluminum alloys have excellent casting performance, low thermal expansion coefficient, good air tightness and wear resistance, and are widely used in automobiles, electronics, communications and other fields. With the continuous improvement of automobile fuel efficiency and energy saving and environmental protection requirements, lightweight and high-strength materials represented by aluminum have been more and more widely used, and its application fields have gradually expanded from traditional appearance parts and non-bearing parts to structural parts, The supporting parts have to withstand sufficient load and thermal fatigue at a high temperature of 350-400 °C for a long time, and the working environment is relatively...

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Problems solved by technology

[0003] Heat-resistant cast aluminum alloys are mainly composed of two series, Al-Si and Al-Cu. Among them, Al-Cu series alloys have good heat resistance, but poor fluidity and corrosion resistance, which hinder the application of alloys; and Al-Si The series of alloys have good casting performance, strong oxidation resistance, good thermal conductivity and low thermal expansion coefficient, and have good application prospects; because the main strengthening phase Mg in Al-Si alloy 2 Si, Al 2 Cu coarsens at 250°C, and the heat resistance is not good, so it is necessary to introduce a high thermal stability phase, such as Al 3 Ni, Al7Cu4Ni, AlFeSi, Al 3 Sc, Al 3 (Zr, Ti, V), Al 4 RE, (Ti,Cr,Mn,V)B 2 etc. Adding Cu and Ni elements in the preparation process is the most common, forming Al-Si-Cu-Mg-Ni heat-resistant cast aluminum alloys, such as ZL108, ZL109, A319 and other brands, and the instantaneous strength at 350 ° C can reach more than 120 MPa, but using The heat-resistant cast aluminum alloy prepared by this method has high cost and low high temperature strength

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