TW201621059A - Magnesium alloy - Google Patents

Abstract

Disclosed herein is a magnesium alloy. The magnesium alloy comprising magnesium (Mg), 6-12 wt% of lithium (Li) and 1-10 wt% of aluminum (Al). A temperature range between solidus and liquidus of the magnesium alloy is ≥ 50 DEG C.

Description

magnesium alloy

This invention relates to an alloy, and more particularly to a magnesium alloy.

Semi-solid metal casting is one of the casting techniques. Smaller grains and better mechanical properties can be obtained by semi-solid metal casting compared to conventional casting techniques. A prerequisite for semi-solid metal casting is that the temperature range between the solidus and liquidus of the metal/alloy used is large, that is, the temperature from the start of melting to the complete melting (solid and liquid phase coexistence zone). The interval should be large to facilitate the control of casting temperature. In this way, a casting having a complicated shape and good mechanical properties can be obtained.

Magnesium alloys are widely used due to their light weight characteristics. Among magnesium alloys, magnesium-lithium (Mg-Li) alloys are the lightest. For example, LZ91 (Mg-9%Li-1%Zn) has a specific gravity of only about 1.5, far more than the current commercial magnesium alloy AZ91 (Mg-9% Al). -1% Zn) is much lower than 1.81. However, the temperature range between the solidus and liquidus is not large. For example, an alloy of magnesium-6 wt% lithium by weight has a solidus liquidus temperature range of only 4 °C. Such alloys are not suitable for use in semi-solid metal casting processes.

The invention relates to a magnesium alloy, which is suitable for semi-solid metal casting by adding various elements to expand the temperature range between the solid phase line and the liquidus line. work. Moreover, such magnesium alloys also have lightweight properties.

According to some embodiments of the invention, the magnesium alloy comprises magnesium (Mg), 6-12 wt% lithium (Li), and 1-10 wt% aluminum (Al). The temperature range between the solidus and liquidus of the magnesium alloy is ≧50 °C.

According to some embodiments of the present invention, the magnesium alloy comprises magnesium (Mg), 6-12 wt% of lithium (Li), 1-10 wt% of aluminum (Al), 0.2-3 wt% of zinc (Zn), ≦0.3 Wt% of manganese (Mn), ≦ 0.2 wt% of bismuth (Si), ≦ 1.0 wt% of calcium (Ca), and ≦ 1.0 wt% of tin (Sn).

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

061, 071, 081, 091, 0101, 0121, 181, 191, 661, 671, 761, 771, 861, 881‧‧‧

Fig. 1 is a graph of a thermal difference analyzer (DSC) according to an example of the present invention (SDT Q600 V20.9 Build 20).

Fig. 2 is a DSC graph of an example of the present invention.

Fig. 3 is a view showing the characteristics of the examples and comparative examples of the present invention.

The present invention relates to a magnesium alloy which can adjust the temperature range between the solidus line and the liquidus by adding various elements. Such magnesium alloys include magnesium (Mg), 6-12% by weight of lithium (Li), and 1-10% by weight of aluminum (Al), and the temperature range between the solidus and liquidus is ≧50 °C. The magnesium alloy is suitable for semi-solid metal casting processing due to its large solidus and liquidus temperature range. In a more preferred embodiment, the temperature range between the solidus and liquidus is ≧95 °C. In addition, in In some embodiments, the magnesium alloy has a specific gravity of less than 1.65. In general, the smaller the density of a metal casting, the greater its specific strength (ratio of strength and density), for example, suitable for use in mobile devices.

Among the magnesium alloys, magnesium is a main component. That is, except for the ratio of the other components described above, the remaining ratio is magnesium. Magnesium is the main component, which makes the magnesium alloy as light as a whole. The addition of lithium reduces the density of the magnesium alloy to less than 1.65 g/cm ³ , but reduces the temperature range between the solidus and liquidus of the magnesium alloy. In general, with the addition of 1 wt% lithium, the liquidus will drop by about 10 ° C, while the solidus line will only drop by about 5 ° C, thus reducing the temperature range between the magnesium alloy solidus and the liquid phase. The addition of aluminum expands the temperature range between the magnesium alloy solidus and the liquid phase, but the alloy density increases slightly. In general, with the addition of 1% by weight of aluminum, the liquidus will drop by about 2 ° C, but the solidus line can be lowered by about 10 ° C, thus expanding the temperature range between the magnesium alloy solidus and the liquidus. By adjusting the ratio of lithium to aluminum, a large solid-phase and liquidus temperature range and a small specific gravity can be obtained at the same time.

Further components may be added to the magnesium alloy. For example, zinc can be added. (Zn), which improves corrosion resistance and lowers the melting point of the alloy. A small amount of manganese (Mn) can be added, which contributes to the strength and corrosion resistance of the alloy. A small amount of bismuth (Si) may be added, which contributes to the strength of the alloy, and since the formation of the magnesium strontium compound during the solidification process releases heat, the casting characteristics can be improved. A small amount of calcium (Ca) can be added which helps to prevent combustion during the semi-solid metal casting process. A small amount of tin (Sn) can be added, which contributes to the high temperature strength of the alloy. Specifically, the magnesium alloy may further include 0.2-3 wt% of zinc, ≦0.3 wt% of manganese, ≦0.2 wt% of ruthenium, ≦1.0 wt% of calcium, and ≦1.0 wt% of tin.

The following examples and comparative examples are used to explain the effects of the present invention in detail. fruit. These examples and comparative examples are all alloys of magnesium-(X wt%) lithium-(Y wt%) aluminum-1 wt% zinc, and the X and Y values of the respective examples and comparative examples are shown in Table 1.

Figure 1 is a DSC graph of Example 4, and Figure 2 is a sample of Example 5. DSC graph. It can be seen from Figures 1 and 2 that the temperature range between the solidus and liquidus of the two is ≧50 °C. The temperature range between the solidus and liquidus of Example 5 is even More than 95 ° C. The specific gravity of the examples and comparative examples and the temperature range between the solidus and liquid phase are shown in blocks 061 to 0101, 0121, 181, 191, 661, 671, 761, 771, 861 and 881 of Fig. 3. Compared to the comparative examples, a larger solid-phase and liquidus temperature range can be obtained according to the examples of the present invention. Further, the specific gravity according to the example of the present invention is less than 1.65, which is lower than the specific gravity of the general magnesium alloy of 1.8.

In summary, the present invention can obtain a magnesium alloy having a large temperature range between a solid phase line and a liquidus by adjusting the types of various elements added and the amount of each added, which is suitable for semi-solid metal casting processing. Moreover, such magnesium alloys also have light characteristics, and are applicable, for example, to mobile devices.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

061, 071, 081, 091, 0101, 0121, 181, 191, 661, 671, 761, 771, 861, 881‧‧‧

Claims (7)

A magnesium alloy comprising: magnesium (Mg); 6-12 wt% (by weight) of lithium (Li); and 1-10 wt% of aluminum (Al); wherein the magnesium alloy is between a solidus and a liquidus The temperature range is ≧50 °C. The magnesium alloy according to claim 1, wherein the temperature range is °95 °C. The magnesium alloy according to claim 1, further comprising: 0.2-3 wt% of zinc (Zn); ≦ 0.3 wt% of manganese (Mn); ≦ 0.2 wt% of bismuth (Si); ≦ 1.0 wt% Calcium (Ca); and ≦ 1.0 wt% tin (Sn). The magnesium alloy according to claim 1, wherein the magnesium alloy has a specific gravity of less than 1.65. A magnesium alloy comprising: magnesium (Mg); 6-12 wt% lithium (Li); 1-10 wt% aluminum (Al); 0.2-3 wt% zinc (Zn); niobium 0.3 wt% manganese (Mn) ≦ 0.2 wt% of lanthanum (Si); ≦ 1.0 wt% of calcium (Ca); ≦ 1.0 wt% tin (Sn). The magnesium alloy according to claim 5, wherein the temperature range between the solidus line and the liquidus line is ≧95 °C. The magnesium alloy according to claim 1, wherein the magnesium alloy has a specific gravity of less than 1.65.