What factors will affect the quality of medical aluminum?

Views:2781 Author:Site Editor Publish Time:2020-06-24 14:05:03 Orgin:Site

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In the market, we often see some low-quality medical aluminum materials. If such materials are used for production work, it will directly lead to poor quality of the produced medical aluminum products. Medical aluminum is light in weight, high in strength, corrosion-resistant, etc., and is generally used in wheelchairs, stretchers, nursing beds, medical accompanying chairs, and medical equipment. Therefore, in order to avoid such situations, when producing medical aluminum materials, we must overcome some factors that affect the quality of medical aluminum materials, such as: alloy element content, aluminum alloy melting furnace, alloy casting level, medical aluminum extrusion, etc. , the following four points will be explained in detail.

     1. Alloying elements

     6063 alloy is an alloy made of aluminum, magnesium and silicon as important elements. Each element has a certain range of content. The price of magnesium is high. In order to reduce costs, some manufacturers reduce the amount of magnesium to a very low level. Medical aluminum is light in weight, high in strength, corrosion-resistant, etc., and is generally used in wheelchairs, stretchers, nursing beds, medical accompanying chairs, and medical equipment. There are also factories that add waste wires and waste pots and waste aluminum pots to the alloy, which is basically not a 6063 alloy. As a result, the mechanical strength of medical aluminum is very low, and it may be so low that it is easy to bend with both hands, commonly known as soft like noodles. This is one of the reasons why aluminum can be as cheap as thousands of dollars.

     Regular medical aluminum manufacturers have internal standards when formulating alloy components, that is, within the content range of various elements, each factory has its own smaller range of changes, and the ratio of aluminum, magnesium, and silicon is very strict. , Each factory has its own data, which are kept secret from each other. Only alloys made with qualified formula can guarantee the quality, otherwise, the quality will not be improved by how to process it in the future.

     2. Aluminum alloy melting furnace

     How to melt the prepared 6063 alloy and what furnace to use are also crucial. At the beginning, the furnaces used in China were at the level of the 1940s and 1990s, and some manufacturers used original crucible boilers. Medical aluminum is light in weight, high in strength, corrosion-resistant, etc., and is generally used in wheelchairs, stretchers, nursing beds, medical accompanying chairs, and medical equipment. There are coal-burning, oil-burning, gas-burning and electric heating smelting furnaces. Some stoves have chimneys, and some stoves have no chimneys. Generally, square furnaces (rectangular furnaces) are used, and circular furnaces are advanced, and some circular furnaces can be tilted to pour aluminum water. In terms of tonnage, there are one-ton, two-ton, five-ton, ten-ton, twenty-five-ton and fifty-ton aluminum melting furnaces. It is more advanced to add a static furnace under the aluminum melting furnace. The static furnace is mainly used for preparing 6063 alloy. It can remove slag and degas in this furnace, let it stand, and then cast aluminum rods for extrusion. The quality of the alloy prepared in the original coal-burning furnace is different from that in the ancient circular furnace. Generally, no matter what kind of fuel is burned, there should be a chimney, and most of the waste gas and residue generated during the combustion of fuel can be discharged from the chimney. If there is no chimney exhaust gas and waste slag are all melted in aluminum water, the aluminum rod for extrusion will be cast in this way, and there will be serious slag inclusion bubbles inside, which is one of the reasons for the poor quality of medical aluminum materials, and it is also one of the reasons for the cheap aluminum price .

     3. Alloy casting

     The level of domestic casting equipment is also very different. The domestic casting equipment has the level of iron mold casting in the 1940s, and the advanced hydraulic semi-continuous casting. The crystallization structure of cast iron cast rods is very poor, and there are a lot of slag inclusions and bubbles in the cast rods, and the quality of cast rods is very poor. At the beginning, some factories used horizontal casting (also known as continuous casting) and semi-continuous casting. , Semi-continuous casting most of the wire rope transmission, good hydraulic transmission. Semi-continuously cast rods vary in length from 3 meters, 4 meters up to 8 meters. The semi-continuous casting is a pit type, casting while falling, and cooling with cold water everywhere, because the water cooling is uniform everywhere, and the crystal structure of the cast rod is uniform and fine. However, the downward transmission of the wire rope is not as stable as the hydraulic transmission, and the surface of the hydraulic casting rod is smoother than other casting rod surfaces. The nominal lubrication of cast rods is one of the prerequisites for extruding good profiles. The surface of the cast rod cast by other methods is relatively rough. In order to ensure the quality of the profile, sometimes the cast rod is turned first to remove the rough surface of the cast rod. The semi-continuous casting mold commonly used at the time is an advanced, hot-top casting mold. The characteristics of this casting mold can cast several to dozens of pieces at a time, and the casting quality is good at the same time. With high-quality 6063 aluminum alloy casting Only rods can produce good medical aluminum materials. If it is impossible to cast good cast rods with primitive and ancient casting equipment, it is basically impossible to produce good medical aluminum materials. There are many medical aluminum factories in China that do not produce aluminum rod equipment, but purchase 6063 alloy rods from electric aluminum factories or other factories. In such aluminum factories, the quality of medical aluminum materials is controlled by the casting rod factory, and the produced High-quality aluminum is difficult to achieve firm quality. Using outdated equipment is better than using advanced casting equipment. First, the investment is small and the production cost is low, which is one of the reasons why the sales price difference of medical aluminum materials is large.

     4. Profile extrusion

     There are many kinds of medical aluminum extrusion machines in my country, with different grades. There are simple extruders of the factory itself, and some are modified by extruding plastic machines. There are a small number of domestic ones, followed by most of them from Taiwan, Japan, the United States and Germany, with water pressure and oil pressure. In short, there are hundreds of extrusion machines in China. It is generally believed that the extrusion machines in Japan, the United States, and Germany are better, followed by Taiwan's good and poor extrusion machines. The same casting rod, the quality of the extruded medical aluminum is absolutely the same. We often see 6063T5 used in the manufacture of aluminum doors and windows, which is an American brand used internationally.

     The Chinese trademark is LD31RCS. Both T5 and RCS indicate the status, indicating the status of air-cooling and quenching artificial aging. The quenching of metal is quenching when high temperature suddenly drops to low temperature. For example, the blade of a steel knife must be quenched in water to be hard and sharp. The quenching of medical aluminum also has water-cooling quenching and air-cooling quenching. The 6063 medical aluminum material used in the production is air-cooled and quenched, and the quenched medical aluminum material is placed in an aging furnace for a certain period of time. The internal crystals of the medical aluminum material are rearranged, and the mechanical strength is significantly improved. Among all alloys of metals, only aluminum alloys have aging conditions.

     Therefore, in order to produce higher-quality medical aluminum materials, producers must not only overcome the above-mentioned influencing factors, but also produce medical aluminum materials in a more standard and reasonable manner!