[Technology] Alloying of Magnesium

Magnesium in its pure form exhibits poor mechanical properties and is unsuitable for structural applications. However, through alloying and heat treatment, the strength of magnesium can be significantly enhanced, making it widely applicable in industries such as aerospace, automotive, machinery, and construction. The primary alloying elements in magnesium alloys include aluminum (Al), zinc (Zn), manganese (Mn), and rare earth elements (RE). These elements exhibit solubility changes in magnesium, enabling the use of heat treatment methods like solid solution treatment and aging to improve the properties of magnesium alloys. Table 11-1 illustrates the chemical composition of cast magnesium alloys used in China. One of the main impurities in magnesium is nickel (Ni), along with iron (Fe), copper (Cu), silicon (Si), and tin (Sn). Among these, Ni is particularly dangerous as it severely reduces the corrosion resistance of magnesium. Nickel has a much higher melting point and density than magnesium but can dissolve easily in magnesium. Therefore, during the smelting process, any equipment or tools must not contain Ni. Although Fe also negatively affects corrosion resistance, its impact is less severe compared to Ni. For example, increasing the Fe content from 0.03% to 0.26% can reduce the corrosion resistance of magnesium by up to five times. Common alloying elements in magnesium alloys include Al, Zn, Mn, Si, RE, Ag, and Cu. Aluminum and rare earth elements enhance both the mechanical and casting properties of magnesium alloys. Manganese forms compounds like AlFeMn, which help reduce the amount of Fe, thereby improving corrosion resistance. Zinc improves both the corrosion resistance and strength of magnesium alloys. Silicon contributes to the formation of hard intermetallic phases, enhancing creep resistance, while silver increases the high-temperature performance of magnesium alloys. Cast magnesium alloys are generally categorized into three types: 1. Mg-Al alloys: Examples include ZMgAl8Zn (ZM5), ZMgAl10Zn (ZM10), AZ91A, AM60A, and AS41A. 2. Mg-Zn-Zr alloys: Such as ZMgZn5Zr (ZMD), ZMgZn4RE1Zr (ZM2), and ZMgZn8AgZr (ZM1). 3. Mg-RE-Zr alloys: Including ZMgRE3ZnZr (ZM3), ZMgRE3Zn2Zr (ZM4), and ZMgRE2ZnZr (ZM6). The latter two categories often contain grain refinement elements and are referred to as "refined magnesium alloys," while the first category is known as "aluminum-magnesium alloys." The development of cast magnesium alloys can be broadly divided into three stages. The first stage focused on adding aluminum and zinc to magnesium, resulting in Mg-Al-Zn alloys. These alloys resemble cast aluminum alloys in terms of tensile strength. Examples include ZM5 in China, L121 in the UK, and AM80A in the US. These alloys mainly rely on aluminum, with relatively low zinc content. However, as the zinc content increases, micro-porosity becomes more common. A major drawback of this type of alloy is its wide crystallization temperature range (around 1570°C), leading to micro-shrinkage and hot cracking during casting. Additionally, the mechanical properties are influenced by the thickness of the casting, with properties tending to decrease as the wall thickness increases. The second phase involved improvements to increase yield strength. In China, ZM1 was developed, while the US introduced ZK51A and the UK used 2970 MAG4P. The addition of zirconium (Zr) significantly refined the grain structure, doubling the yield strength and improving fatigue resistance and notch toughness. However, the wide crystallization range still posed challenges, such as microporosity and hot cracking. To further enhance performance, some alloys incorporated rare earth elements, such as ZM2 in China, 2970 MAG5P in the UK, and ZE41A in the US. The third phase marked the development of high-performance alloys designed for improved creep resistance at elevated temperatures. Examples include ZM3, ZM6 in China, DTD5051 in the UK, and HK31Ao in the US. Some alloys, like Mg-Zr-Ag-RE, incorporate silver to achieve optimal yield strength and creep resistance. Others, such as those containing niobium, offer high specific strength, though their high cost limits widespread industrial use. Despite these limitations, the continuous evolution of magnesium alloys demonstrates their growing importance in modern engineering applications.

Solar Light

Solar street lights have several advantages over traditional street lights. Here are some of the benefits of solar street lights:

Energy-efficient: Solar street lights are powered by renewable energy from the sun, making them highly energy-efficient and eco-friendly. They do not require electricity from the grid, which reduces electricity bills and carbon emissions.
Although the initial cost of installing solar street lights may be higher than traditional street lights, they are more cost-effective in the long run. They require minimal maintenance and have a longer lifespan, reducing replacement and repair costs.
Solar street lights are easy to install and can be installed in remote areas without access to electricity. They do not require any wiring or trenching, which makes the installation process quick and hassle-free.
Solar street lights provide better visibility on roads and sidewalks, making them safer for pedestrians and drivers. They also reduce the risk of accidents and crime in poorly lit areas.
Solar street lights are equipped with batteries that store energy during the day and provide power at night. They are designed to work even in cloudy weather and can provide illumination for several nights without sunlight.

solar street lamp,solar light,solar power,solar panels,solar street light

Yangzhou M.T. New Energy & Lighting Group Co., Ltd. , https://www.mtstreetlight.com