Tungsten alloy, also called tungsten for short, is used as a new lead-free small caliber core for national defense. Small caliber cores rages from 9mm to 0.50 caliber including 5.56mm, 7.62mm, 9mm, 0.38 and 0.45 caliber, etc., could be produced by tungsten mixtures metal with the same techniques used for the construction of lead-containing bullets but without any poison to environment. It is just as lethal as the standard core of 5.56mm without harming the environment. The day end the use of environmentally hazardous materials in small caliber cores for all ammunitions is coming.
Besides, as a high density metal, tungsten is mixed with the binder such as nickel, iron, copper, cobalt, etc. to produce the components with controlled density and mechanical properties. Powder metal mixtures such as tungsten small caliber core is simply cold pressed to produce a high-density material with superior properties, e.g. high hardness, good ultimate tensile strength, excellent elongation, etc.
Main Manufacture Process of Tungsten Small Caliber Core
Tungsten small caliber core is manufactured by powder metallurgy technique with some complex process. The main manufacture process is mixing, de-waxing, pressing, sintering, machining, and then move to surface control if there is a need, such as electroplating, engraving, etc. Heat treating is very necessary to achieve the appropriate properties for tungsten small caliber core, elongation would be improved by that process.
The combined processes of mechanical interlocking and "cold-welding" bond the metals together, and can be varied to control the properties of the non-lead core. Tungsten small caliber core can be pressed directly to shape, or cores can be produced that can be swaged into projectiles, with or without jacketing. So swaging is another important process for reaching a higher hardness at least 40HRC, meanwhile, ultimate tensile strength could be also increased to at least 1050Mpa. If the properties are needed higher, some of the processes would be adjusted.
Tungsten Small Caliber Core Properties: The powder metallurgy approach has the potential not only to produce quality high density, non-toxic cores that are a direct replacement for lead, but also to revolutionize many of the aspects of core design and performance. Customerized tungsten small caliber core is warmly welcomed with high properties as follows:
High hardness 40HRC min. (Regular tungsten material only about 28HRC)
Excellent ultimate tensile strength 1050MPa min. (Regular tungsten material only about 900Mpa)
Non-toxic to the environment Superior machinability