JP2019507248A - Age hardening type Al-Mg-Si based aluminum alloy - Google Patents

Abstract

It shows about an age hardening type Al-Mg-Si type aluminum alloy. In order to obtain an aluminum alloy that is easy to recycle and is stable to stand, particularly an artificial age-hardening type aluminum alloy, the aluminum alloy contains 0.6 to 1% by weight of magnesium (Mg), 0.2 to 0.7% by weight. Silicon (Si), 0.16-0.7 wt% iron (Fe), 0.05-0.4 wt% copper (Cu), up to 0.15 wt% manganese (Mn), up to 0 .35 wt% chromium (Cr), up to 0.2 wt% zircon (Zr), up to 0.25 wt% zinc (Zn), up to 0.15 wt% titanium (Ti), 0.005- Containing 0.075 wt% tin (Sn) and / or indium (In), and the balance aluminum, as well as inevitable impurities in manufacture, wherein the weight percentage ratio of Si / Fe is less than 2.5; Si content is a parameter There is proposed to be determined according to Equation 1 Equation 1] below in the range of 0.17 to 0.4 wt%. [Selection] Figure 2

Description

  The present invention relates to an age-hardening Al—Mg—Si-based aluminum alloy.

  In order to improve the A6061 (Al-Mg-Si-based) aluminum alloy that has been naturally aged by being left at room temperature, Patent Document 1 discloses a vacancy-active trace element, ie, tin (Sn) and / or a solid solution of an aluminum alloy. Alternatively, it is proposed to add indium (In).

  Furthermore, certain major alloy elements and suballoy elements of the A6061 aluminum alloy reduce the solubility of tin or indium in the aluminum alloy, which is known to adversely affect the room temperature stability of the 6000 series aluminum alloy at room temperature. (Non-Patent Document 1). Therefore, for example, a 6000 series aluminum alloy with a high content of Mg, Si, Cu, or Zn decreases the solubility, while Fe, Ti, and Mn improve the solubility. Furthermore, for example, the interaction effect between Si and Mg and / or Cu and Mg also plays an important role in the solubility of Sn in the aluminum alloy.

  However, the contents of the main alloy element and suballoy element in the aluminum alloy cannot be arbitrarily changed. In addition to the desired height of artificial age hardening, other mechanical and / or chemical requirements such as formability, strength, ductility and / or corrosion resistance must be met. For this purpose, for example, it is necessary to increase the concentration of the main alloy element in the aluminum alloy so that a specific high-temperature precipitate can be formed.

  For this reason, adjustment of the composition of the aluminum alloy usually requires a relative proportion ratio between the main alloy element and the suballoy element. That is, on the one hand, it is advantageous for the solubility of Sn in the aluminum alloy, and on the other hand, it takes into account the mechanical and / or chemical characteristic value of the aluminum alloy, that is, the property, which realizes high standing stability at room temperature. However, it is a quantity ratio that often negatively affects the solubility of Sn.

International Publication No. 2013/124472

Stefan Pogatscher et. al, "Statistical and thermal optimization of trace-element modified Al-Mg-Si-Cu Alloys", Light Metals 2015, p. 265-270

  Therefore, the object of the present invention is to change the composition of an Al—Mg—Si age-hardening aluminum alloy containing Sn as a trace element, so that an artificial age-hardening aluminum alloy has high mechanical and / or chemical properties, It is to be able to combine high standing stability at room temperature. Furthermore, this aluminum alloy is particularly suitable for the use of secondary aluminum.

  In the present invention, the aluminum alloy is composed of 0.6 to 1% by weight of magnesium (Mg), 0.2 to 0.7% by weight of silicon (Si), 0.16 to 0.7% by weight of iron (Fe). 0.05 to 0.4 weight percent copper (Cu), up to 0.15 weight percent (ie, 0 to 0.15 weight percent) manganese (Mn), up to 0.35 weight percent (ie, 0 to 0.0. 35 wt%) chromium (Cr), up to 0.2 wt% (ie 0-0.2 wt%) zircon (Zr), up to 0.25 wt% (ie 0-0.25 wt%) zinc (Zn), up to 0.15 wt% (ie 0-0.15 wt%) titanium (Ti), 0.005-0.075 wt% tin (Sn) and / or indium (In), and the balance Contains aluminum and impurities inevitable in production, and at this time, Si / F The weight percentage ratio is less than 2.5, and the content of Si is determined according to the following formula 1 in which the parameter A is in the range of 0.17 to 0.4% by weight, thereby solving the above problem. .

  In addition to limiting the Si content to 0.2-0.7 wt% and the Fe content to 0.16-0.7 wt%, specify that the Si content and Fe content be adjusted Thus, when this adjustment satisfies the following formula 2 in which the weight percent ratio of Si / Fe is less than 2.5 and the parameter A is in the range of 0.17 to 0.4 wt%, Al -It can affect the standing stability and artificial age hardening ability of the Mg-Si based aluminum alloy particularly advantageously.

  Thus, the aluminum alloy in which the Si content and the Fe content are strictly adjusted (such adjustment can be confirmed in, for example, the hatched portion in FIG. 1), that is, the tin and / or the solid solution of the aluminum alloy by the upper limit specified above. Or sufficient solubility of indium can be guaranteed. As a result, the precipitation behavior is delayed during natural aging, thereby promoting the standing stability of the aluminum alloy. Furthermore, the lower limit of the adjustment allows sufficient precipitation behavior to be expected during artificial aging, so that high strength values can be reached during artificial aging, and the aluminum alloy itself is composed of the main alloy elements and suballoy elements. Mechanical and chemical properties such as are known for high content 6000 series aluminum alloys can be realized or improved.

  Surprisingly, however, it was found that when this rule is used, precipitation behavior delayed many times at room temperature can be observed as compared to known 6000 series aluminum alloys containing Sn in order to suppress spontaneous age hardening. Certainly, it is known that a relatively low Si content can cause a delay in natural age hardening, but adjusting the Si content according to the present invention far exceeds this known effect, and aluminum alloys It shows exceptionally high storage stability.

  Therefore, according to the present invention, it is possible to combine the advantages of the aluminum alloy that the standing stability at room temperature is particularly high and the artificial age hardening ability is excellent.

  Furthermore, this composition according to the invention may be particularly suitable for the use of secondary aluminum for this because of the relatively high Fe content.

  In general, it is mentioned that Al-Mg-Si-based aluminum alloys may each contain up to 0.05% by weight of impurities, and at most 0.15% by weight in total. More generally, it is mentioned that the indication of the maximum weight percent found, for example, in Mn, Cr, Zr, Zn, or titanium can be regarded as starting from zero.

  For the sake of completeness, it is mentioned that the aluminum or aluminum alloy obtained from aluminum scrap can be understood as secondary aluminum.

  The standing stability and artificial age hardening ability of the aluminum alloy can be further improved when the parameter A is in the range of 0.26 to 0.34% by weight. This definition, that is, the solubility of Sn is relatively large, so that Si has a slight effect on natural age hardening. Thereby, unexpectedly high stability can be realized at room temperature. Furthermore, alloys prepared in this way can reach surprisingly high strength after artificial age hardening (eg by holding at elevated temperatures), despite the relatively low Si content of the alloy.

  When the parameter A is 0.3% by weight, optimum standing stability and artificial age-hardening ability can be shown.

  If the Si content is determined according to the following Equation 3, the components affecting the solubility of Sn can be further improved and adjusted to each other. Specifically, Ti can form a phase with Si, which can positively affect the solubility of Sn. Thereby, the standing stability of the aluminum alloy can be further improved.

  If the weight percent ratio of Si / Fe is less than 2, solidification of Si proceeds by Fe, so that the content of dissolved Si in the aluminum alloy can be greatly reduced. Thereby, the solubility of tin and / or indium in the solid solution of the Al—Mg—Si based aluminum alloy can be improved, and the standing stability can be further enhanced.

  When the weight percentage ratio of Si / Mg is in the range of 0.3 to 0.9, the solubility of tin and / or indium in the solid solution of the Al—Mg—Si based aluminum alloy can be made relatively high.

  When the aluminum alloy contains at least 0.25 wt% copper (Cu), the relatively high Cu content results in Mg and Sn relative to the solubility of Sn in the solid solution of the Al-Mg-Si based aluminum alloy. The adverse effects of Si can be counterbalanced.

  When the aluminum alloy contains tin (Sn) in the aluminum mixed crystal solid solution in the range of 0.005 to 0.05% by weight, excellent standing stability of the aluminum alloy can be obtained. In general, the term “solid solution” is mentioned to be able to refer to a state in which alloying elements are dispersed in a solid matrix.

  Preferably, the aluminum alloy belongs to the 6000 series. Preferably, the aluminum alloy is EN AW-6061 aluminum alloy.

  If the aluminum alloy contains up to 0.05 wt% chromium (Cr) and more than 0.05 wt% zircon (Zr), it reduces the Sn susceptibility to quenching, even at relatively slow quenching rates. It can be held in a solid solution of crystals. In addition, even with a thick plate, optimum standing stability and artificial age hardening can be obtained.

  The aluminum alloy can optionally contain at least 0.02 wt% chromium (Cr) to improve the corrosion behavior.

It is a table | surface which shows content of Si and Fe in an aluminum alloy. It is a table | surface which shows the leaving period [d] and Brinell hardness [HBW] of an aluminum alloy. It is a table | surface which shows the artificial aging temperature [degreeC] and Brinell hardness [HBW] of an aluminum alloy.

  In order to prove the obtained effect, thin plates made of various Al—Mg—Si (6000) aluminum alloys were produced. The composition of the tested alloys is shown in Table 1.

  The aluminum alloy 1 in Table 1 basically corresponds to the standard alloy AA6061 after adding the trace element Sn, and it is conceivable to use indium or a combination of Sn and In instead of tin. Alloy 2 is a 6000-based composition according to the present invention and is relatively easy to recycle because of its relatively high Fe content.

  The aluminum alloy 1 is clearly deviated from the Si / Fe content adjusted according to the present invention, which can be confirmed, for example, in FIG. The aluminum alloy 2 is located approximately at the center of the adjusted Si / Fe content.

  Both aluminum alloys 1 and 2 were solid-solubilized by solution heat treatment, quenched, and then subjected to natural age hardening treatment by aging at room temperature, and then artificial age hardening treatment. The solution heat treatment was performed at a temperature exceeding 530 ° C., and the quenching was performed at a quenching rate exceeding 20 ° C./second. Both alloys 1 and 2 were subjected to a standing period of 180 days [d], that is, a natural age hardening treatment and an artificial age hardening treatment for 30 minutes at various temperatures. Brinell hardness [HBW] was measured during the natural age hardening treatment or after the artificial age hardening treatment.

  With respect to the standing stability, it can be confirmed in FIG. 2 that the alloy 1 has been relatively hardened by aging after 14 days after standing at room temperature. This has the disadvantage that the Brinell hardness has risen relatively high when viewed over a long standing period and adversely affects the deformation before the artificial age hardening.

  In contrast, it becomes clear that alloy 2 finally begins spontaneous age hardening after approximately 180 days, so that alloy 2 according to the present invention is considered to be particularly stable. Such a surprisingly high storage stability has not been observed so far for 6000 series alloys. This results in an unexpected significant utility in the processing time of the alloy in the soft state after quenching.

  In the subsequent artificial age hardening, when the two alloys are compared in FIG. 3, it can be confirmed that the alloy 2 is delayed from the alloy 1 for the time being in the Brinell hardness at a lower aging temperature. As the aging temperature increases, the Brinell hardness of Alloy 1 can be clearly exceeded.

Claims (11)

Age-hardening Al-Mg-Si-based aluminum alloy,
0.6-1 wt% magnesium (Mg),
0.2-0.7 wt% silicon (Si),
0.16 to 0.7% by weight of iron (Fe),
0.05 to 0.4% by weight of copper (Cu),
Up to 0.15 wt% manganese (Mn),
Up to 0.35 wt% chromium (Cr),
Up to 0.2% by weight of zircon (Zr),
Up to 0.25 wt% zinc (Zn),
Up to 0.15 wt% titanium (Ti),
0.005 to 0.075 wt% tin (Sn) and / or indium (In),
As well as the balance aluminum, and impurities inevitable in production,
The weight percent ratio of Si / Fe is less than 2.5;
The following formula 1 in which the Si content is such that the parameter A is in the range of 0.17 to 0.4 wt%
Aluminum alloy determined according to.   The aluminum alloy according to claim 1, wherein the parameter A is in the range of 0.26 to 0.34 wt%.   The aluminum alloy according to claim 1 or 2, wherein the parameter A is 0.3% by weight. The content of Si is the following formula 2
The aluminum alloy according to claim 1, wherein the aluminum alloy is determined according to claim 1.   The aluminum alloy according to claim 1, wherein the weight percentage ratio of Si / Fe is less than 2. 5.   The aluminum alloy according to any one of claims 1 to 5, characterized in that the weight percentage ratio of Si / Mg is in the range of 0.3 to 0.9.   The aluminum alloy according to claim 1, wherein the aluminum alloy contains at least 0.25% by weight of copper (Cu).   The said aluminum alloy contains tin (Sn) in the range of 0.005-0.05 weight% in the solid solution of an aluminum mixed crystal, It is any one of Claims 1-7 characterized by the above-mentioned. Aluminum alloy.   The aluminum alloy according to any one of claims 1 to 8, wherein the aluminum alloy belongs to the 6000 series.   10. The aluminum alloy according to any one of claims 1 to 9, characterized in that it contains up to 0.05 wt% chromium (Cr) and more than 0.05 wt% zircon (Zr). Aluminum alloy.   The aluminum alloy according to any one of claims 1 to 10, characterized in that the aluminum alloy contains at least 0.02 wt% chromium (Cr).