Powdered Metal Gears
Powdered metal gears, or powder metal gears, are a type of powdered metal part. Fabricated using various possible metallurgy techniques, the mission of this mechanical hardware is to transmit speed, power, motion and directional speed between axes. They are widely, though very specifically, used in industries such as power generation, aerospace, robotics, agriculture, pharmaceutical, automotive, petrochemical, building and construction, military and defense, marine transportation, medicine and material handling.
Quick links to Powdered Metal Gears Information
On top of this, powdered metal gears can be created uniformly and repeatedly. This fact makes them even more cost-effective to produce. Also, powdered metal parts are porous. Porosity both lightens the weight of a gear and dampens sound; to serve the unique needs of various applications, this feature can be easily and closely controlled using steam filtration and infiltration of the pores using a metal with a lower melting point and resin or oil impregnation. Note that the last of these methods, resin or oil impregnation, adds a self-lubricating feature to gears, thereby prolonging both their working life and the working life of the motor with which they are paired. For more information on powdered metal gears, contact an experienced gear manufacturer or metal part manufacturer, such as those listed on this page.
To meet the various needs of the many applications for which they are in demand, powdered metal gears are available in a number of different styles, including helical, hypoid, herringbone, anti-backlash, bevel, chance, cluster, differential, milter, planetary, spur and pinion and internal. Gears such as these vary according to details such as the number of teeth, tooth forms, pressure angles, gear centers, gear directions, mounting requirements, design units, and more. Gears, regardless of their type, may be made up of either a single metal material or a composite material. Metals and metal alloys frequently used to make powdered metal gears include carbon steel, alloy steel, stainless steel, cast iron, brass, bronze, titanium, aluminum, and magnesium.
These gears, when produced using powder metallurgy, are created using three main steps. First, solid metal stock shapes or bars are converted into a fine metal dust or powder. This can be done using a variety of different techniques, among them centrifugal disintegration, flaking, pulverization, chemical decomposition, grinding and atomization. Most often, manufacturers choose to convert solid metal into powder using atomization. This is because, by separating molten metals into separate particles that then freeze into solid form, this process can effectively process nearly all metals. At this time, if a manufacturer so chooses, a pure metal may be enhanced with another metal to make an alloy or with additives that provide lubrication. Either way, the second step is the forming portion of the powder metallurgy process. In this step, predetermined amounts of the powdered metal are poured into a mold cavity or a compaction die that has been prefabricated in the desired finished shape of the gear. Then, large amounts of pressure, precisely measured to fit the specific materials in the mold and intended use of the finished gear, is applied to the mold from both above and below. Under this pressure and at room temperature, the metal is compacted until it becomes solidified. Note that the exact amount of pressure applied to the metal determines its malleability as a finished gear. Next, the third step of powder metallurgy is sintering. This begins with the ejection of the formed metal mass from the mold or die. Once free of the mold, the metal gear form is placed on a moving belt that draws it into an extremely hot furnace, where the part is heated almost but not quite to its melting point. As a rule, the furnace is heated to a controlled temperature that is two thirds of the melting point of the primary metal. By heating the raw materials of the metal gear to this point, the particles of the metal are able to fuse together without melting and convert their mechanical bonds into metallurgical bonds. The result of sintering is a strong, porous, and rigid metal piece.
Pressing and Sintering Processes
Though gears can be fabricated using many different machining processes, powdered metal gears and powder metal parts, in general, offer their users many different benefits that traditionally formed gears and parts simply do not. Included in this list are properties such as versatility, close tolerances, cost-effectiveness, and porosity. Press and sinter processing, as it is sometimes known, allows for great versatility in terms of what manufacturers can produce and how they can produce it. Press and sintering processes can, for example, be used to create gears with internal configurations, gears with very close tolerance components and multilevel gears. This useful ability reduces or eliminates the need for secondary operations, and manufacturers can save both time and money without secondary operations.