Methods for prevention of ignition during machining of magnesium. The results obtained at ambient temperature will provide a baseline for the study of the corrosion of magnesium alloys in hot, flowing coolants. I have evaluated 16 waterbased coolants for use on magnesuim in the last 6 months including lighting lots of fires. Some of them are wrong and their machine coolants actually dissolve more cobalt. Machining magnesiuma study of ignition factors springerlink. Our products provide superior cooling, cleanliness and long emulsion stability. Dec 06, 2004 developing a safer way to machine magnesium machining magnesium is risky business, as the chips and dust generated are flammable.
Never use water to extinguish magnesium because the burning magnesium will decompose water to form hydrogen which is easily ignited. Apr 16, 20 people in the machining industry tend to think of coolants and metalworking fluids as a necessary evil. The oil functions primarily as a coolant, reducing the risk of fire, which is common to magnesium machining. Some of them are partially right and their machine coolants dissolve cobalt more slowly than other machine coolants. I want to know what precautions i should be taking when machining magnesium alloy bar, with particular regard to fire risk. However, there may be times when further cooling of the workpiece. Should a fire occur, dry turnings will burn slow and evenly. Corrosion of magnesium mg alloys in engine coolants. High speed machining of magnesium and its alloys sciencedirect. I want to know what precautions i should be taking when machining magnesium alloy. Alcoholbased coolant offers environmentally friendly machining this microvolume coolant delivery system uses ethanol as the cooling medium for nonferrous workpieces. If when necessary to use coolant, a light mineral oil will suffice.
Therefore, fully understanding the corrosion behaviour and mechanism of magnesium immersed in ethylene glycol solutions is an essential step prior to identifying successful coolants for magnesium alloys. Over the years, semisynthetic machining and grinding coolants have compiled an inconsistent service record and earned a reputation for performing well, but just not well enough. The following list of safety precautions and machining tips for machining magnesium are recommended in conjunction with normal safety practices. The use of oilbased coolants reduces, but doesnt eliminate, the fire risk. This increases the risk of fire due to the oil mist that forms during the machining process. People in the machining industry tend to think of coolants and metalworking fluids as a necessary evil. Where coolants are desired, only mineral oit cutting fluids should be used. Metallurgical considerations for machining magnesium alloys jstor. Therefore, in the machining of magnesium alloy parts, the cutting fluid is generally referred to as a coolant. Semisynthetic coolants machining coolants texas coolants. Methods for prevention of ignition during machining of magnesium alloys. Sparks and flares are potentional ignition sources in dry magnesium machining.
Alcoholbased coolant offers environmentally friendly machining. Traditionally a low viscosity oil has been the recommended cutting fluid for magnesium. The potassium chloride fire powder extinguisher is the best extinguisher, other common extinguishers such as cast iron turnings and dry sand. Magnesium is the third most commonly use structural metal after iron and aluminium and historically has been used in applications including german aircraft during world war 1. The possibilty of chips or turnings catching fire must be considered when machining magnesium. Fire behaviour of magnesium alloys magnesium alloys factor of risk. Manufacturing with a 3 axis milling machine creates parts and components, and it generates heat. Low power required approximately 55% of that required for al. Optimization of machining parameters for magnesium alloy using taguchi approach and rsm r. Keep a container of cast iron chips near by when machining magnesium, if fire happens, surround the fire with the cast iron chips. Coolants for challenging cuts cutting tool engineering. Thirdly, if coolants are needed for high speed machining, do not make use of waterbased lubricating substances. While we were machining some magnesium angle plates, 7 by 8 by 14, about 1 and 34 thick, we were cleaning up the shop quite regular.
Though coolants can be used effectively to prevent ignition, the. An expertly developed, customformulated metalworking fluid, manufactured by a specialty chemical company with unparalleled expertise, is the only way to assure the best performance of any metalworking operation. Safety machine coolants there seem to be many sales people in the market selling machine coolants that will not dissolve cobalt. Other than that, the pollution of the environment and reclamation of chips cannot be resolved quickly when using coolants during machining process. Methods for prevention of ignition during machining of. Use of water containing fluids for coolants is not recommended. Cutting magnesium on the band saw practical machinist. Always have dry sand, flux such as m310, or a class d fire extinguisher available when. Some of the advantages of machining magnesium compared to other commonly used metals include. Hangsterfers policy on magnesium machining with water soluble coolants as magnesium gains application popularity due to its high strength and lightweight characteristics, the issue of proper coolant selection for magnesium is becoming more prevalent. Coolants and swarf have no rightful place in your working environment.
Machine tool industrial lubricants liquid ice 4000, the high performance, synthetic, water soluble coolant and lubricant for industries that do high temperature or. Magnesium products limited in making the transi tion from dry machining to wet machining with a water base coolant. The product selection survey submitted by our representatives to the machining coolants technical staff provides a complete picture of your procedures, from stock to finished product, allowing us to find you the best custom metalworking fluids and compounds that match your precise needs. Many manufacturing leaders, whether in a small job shop or in a huge multinational automotivesupply plant tend to think of coolant only when there is a problem or perceived problem with it within the facility. Mineral seal oils and kerosene have been successfully used as coolants for magnesium alloy processing.
Cutting fluids coolants cutting fluid metalworking fluid, coolant is a liquid used in metalworking operations for reducing friction between the work piece and the tool and for removal of the heat generated by the friction. Machine tool industrial lubricants coolants liquid ice. Pdf methods for prevention of ignition during machining of. An extensive series of tests was conducted to determine limits within which magnesium machining fires can be avoided or minimized through adjustment of environment and machining conditions. Never use water based coolant because of the risk of any reaction with the chips during storage. Airbench knows exactly what you need we have the necessary industry experience to effectively deliver the best cleaning solution for you and your company. The paper details the plants prior experience with dry machining, and its current experience with the. Powder or dust from grinding or other operations can present an explosion hazard. Roughing cuts and medium finishing cuts produce chips too large to be readily ignited during machining.
The main concern in machining magnesium alloy is the danger of fire ignition when dry cutting. Potential problems when machining of magnesium and its alloys are illustrated in figure 1. In the download section is the special machining datasheet available. When machining with water soluble coolants one can expect.
Application of cryogenic coolants in machining processes. Alcohol based coolant offers environmentally friendly machining. Highspeed tools or carbide tipped tools are preferred for the machining of magnesium. Therefore, one better approach is to control the machining parameters for minimizing ignition hazard of magnesium alloy chips during dry machining. The suppression system put the fire out before the operators had even realized there was a fire. Magnesium machining is normally done without any coolant. Ramesh abstract magnesium alloy is one of the lightest materials which has wide applications in the production of aircraft engines, airframes, helicopter components, light trucks, automotive parts and computers parts for its. Brighton laboratories full product line of machining coolants were developed for the machining and grinding of all ferrous and nonferrous metals. Optimization of machining parameters for magnesium. Many manufacturers have turned to oilbased coolants to achieve greater precision in automotive, medical, aerospace, and other machining applications. We recently had quite a bit of magnesium in the shop we had to machine parts from, and it almost resulted in a fire while in the milling machine. It is becoming much more common that cast and fabricated magnesium alloy parts will undergo cnc machining.
Specifications of aluminum machining coolants include 1. Jun 14, 2006 alcohol based coolant offers environmentally friendly machining this microvolume coolant delivery system uses ethanol as the cooling medium for nonferrous workpieces. A research consortium has developed a novel way to extract magnesium particles out of the machine by vacuuming them through a hollow tool and spindle during machining. Thirdly, if coolants are necessary for high speed machining, do not use waterbased lubricants. Understanding fire risks and fire protection options for cnc. A class d ansul metal fire fire extinguisher should be in the immediate vicinity of the machining activity. Optimization of machining parameters for magnesium alloy. Water soluble coolant is not recommended, as magnesium and water are highly reactive. Machining operations in this plant consist of milling, boring, broaching, drilling, tapping and stud driving. Custom machining and grinding coolants international. In some machining and grinding operations, a little mineral oil can go a long way. Magnaloycouplingcompany technicalproductinformation couplings thepossibilityoffirewhenmachiningmagnesiumisalwaysarealconcern.
In addition, the magnesium particles mixed in oil cant be recycled, and the machined parts would require extensive cleaning to remove oil residue. Chips must be heated close to thier melting point before ignition can occur. Safety measures related to machining, handling of chips and fines, and fire. Brighton labs coolants are formulated for a broad range of machining applications and materials including aluminum. Fine finishingcuts,however,produce fine chips that can be ignited by a spark. You may make both very fine magnesium particles and hot water machining with water based coolant.
Therefore, the interest in magnesium and its alloys have grown dramatically in research community to identify new machining technologies in order to prevent ignitionduring machining as well as reducing their cost of production ruzi et al. Though coolants can be used effectively to prevent ignition, the pollution of environment and reclamation of chips can not be resolved easily. Since 1968, specmaster has been an industry leader in machining a variety of complex parts from magnesium. When in contact, magnesium and water generate heat, which, in the presence of highly combustible magnesium fines, creates a serious fire. It is part of my job to select, test and specify the coolant we use to machine tons of magnesium. Keep a container of cast iron chips near by when machining magnesium, if fire occurs, smother the fire with the cast iron chips. The owner of the shop not liking to have the chips setting around, took them outside and placed them bag and all on the burning camp fire. The small chips and fine dust generated during cutting are also highly flammable and pose a serious fire risk if not properly handled. Developing a safer way to machine magnesium machining magnesium is risky business, as the chips and dust generated are flammable. However, there is a limited choice for coolant when machining magnesium alloy, as it can react with water and other oilbased coolants too. Coolants containing water should not be used because of the fire danger when magnesium chips react with water, forming hydrogen gas. Machining magnesium magnesium is the lightest structural metal and exhibits excellent machinability. The danger of magnesium and water comes from two sources, the first is that once the magnesium is on fire, magnesium fire burns.
Machining of magnesium and magnesium alloys asm digital library. There are now several types of machine coolants on the market, the most common of which can be broadly categorized as cutting oils or watermiscible fluids. Low power required approximately 55% of that required for al fast machining employing the use of high cutting. This problem has attracted considerable research interests. Machine coolant health and safety carbide processors. The ethanol evaporates after it cools the cutting tool, so no residue is left behind on machined workpieces. Our skilled machinists have years of experience and an extensive knowledge of various machining strategies to produce your magnesium components. Without the correct coolant, machines break down, and prior to. The desirable properties of cutting fluids in general are boston, 1952 1 high thermal conductivity for cooling. Any way, the 50 pound dog food bag got full before we finished. Magnesium usually does not react with water, but oil based coolants would probably be better, because magnesium can react with very hot water, ie steam, and very small magnesium powder is more reactive than big magnesium chips. Cnc fire protection firetrace fire suppression systems. The possibility of fire when machining magnesium is always a real concern.
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