Examples of applications of strontium hydride

Background and overview
Strontium hydride (SrH2) is a white crystal with a relative density of 3.27, which can be sublimated. Strontium hydride reacts violently with water to form strontium hydroxide and hydrogen, and moderately reacts with alcohol to form strontium alcoholate. The mixture with chlorate, perchlorate and chromate can explode when heated a little. It can be obtained by direct combination of hydrogen and strontium or reduction of strontium oxide or strontium chloride with hydrogen. Strontium hydride is used as a condensing agent and reducing agent in organic reactions.

application
Metamorphism can greatly improve the comprehensive mechanical properties and chemical stability indicators of aluminum alloys, and sometimes even subversive. Substances that can produce metamorphic effects are called metamorphic agents.

CN201110398124.6 Aiming at the defects existing in the modification of sodium salt modifying agent and the modification of aluminum-strontium intermediate alloy, strontium hydride is used as a high-efficiency modifying agent, and is added to the alloy melt in a fluidized manner with protective gas. The metamorphic element Sr in the atomic or ionic state is released by chemical reaction or high temperature decomposition, and diffuses into the aluminum melt quickly and uniformly to achieve the purpose of efficient and uniform metamorphism and purification of the melt, and realize the fine grain size of the matrix and metal compound phase. and replace the intermediate alloy in the production of aluminum alloy, reduce the intermediate links, save energy and reduce consumption. The technical scheme of the present invention is that a high-performance aluminum alloy material modified by strontium hydride is composed of Cu: 1.4-1.5%, Mn: 0.4-0.5%, Mg: 1.5-2.0%, Cr in weight ratio : 0.1~0.2%, Zn: 4.0~4.5%, Ti: 0.01~0.15%, Si: ≤1.0%, Fe: ≤1.0%, the modifier SrH2 is 0.15~0.2% of the total charge, and the rest are Al and non-ferrous metals. Trace impurities to be avoided, and the content of impurity elements is: individual ≤ 0.03%, total ≤ 0.15%.

The preparation method includes the following steps:

Step 1: Within the above element ratio range, select a group of elements and the ratio of modifier SrH2, and then calculate the required quality of each composition according to the total amount of alloy to be prepared, compile the alloy production ingredient list, and press the ingredients. The table selects enough materials;

Step 2: Add aluminum ingot or molten aluminum into the smelting furnace, heat it to completely melt and keep it at 700-800°C; the melting process is completed in a closed environment;

Step 3: Add the alloying elements selected in Step 1 according to the formula ratio to completely dissolve and melt, and stir the mixed melt evenly;

Step 4: then carry out in-furnace refining on the above-mentioned alloy melt; add a refining agent to the alloy melt, stir evenly, and operate the melt refining in a closed environment;

Step 5: After refining and slag removal, the melt is degassed with the protective gas nitrogen, and the modifier SrH2 is added to the alloy melt in a fluidized manner along with the protective gas nitrogen; at the same time, stirring is performed to make the modifier SrH2 SrH2 fully reacts with the alloy melt; after the modification agent is added, continue to introduce protective gas nitrogen until the modification agent reaction is completed;

Step 6: stand, adjust the temperature to 700-800°C, pour the alloy liquid out of the furnace, and enter the next process.