Document Type : Original Article
Authors
1
Dr. Eng. Scientific Researcher, Dpt. Of Special Alloys - Sintered Products, Metallurgical Research Institute, Bucharest, Romania.
2
Senior Researcher, Dpt. Of Special Alloys - Sintered Products, Metallurgical Research Institute, Bucharest, Romania.
3
Professor Dr. Eng., Dpt. Of Materials Science, POLITEHNICA University, Bucharest, Romania.
4
Senior Researcher, Dpt. Of Metallurgical Work, Prelucrari Metalurgice Ltd., Bucharest, Romania.
5
Professor Dr.Lt. Col., Dpt of the Advanced Distributed Learning , „ Carol I” National Defence University, Bucharest, Romania.
Abstract
After 11th September 2001, the global security environment has changed radically, passing from symmetrical to asymmetrical risks and threats. This is especially based on using different forms at rapid reaction based on using advanced technologies in the field of communications sensors and ammunitions. The researches in the military field are working on identifying those solutions which will allow counter acting those asymmetric actions through using conventional military means, and through increasing their efficiency and reducing the collateral damages. Nowadays, in medium and long range military actions are used 8360 tones of conventional ammunition per 5 days of action (implying large quantities of materials with negative impact on the environment), which have efficiency of max 50% from their real potential. From the data obtained so far, in Iraq 300,000 tones of ammunition with different purposes were used, from which more than 60% were used in urban areas with recognized implications on the environment and the social and economical activities in the area. Through using other technologies to create ammunition (intelligent and nonpolluting) it is considered that at a reduction of 30% of their quantity, their efficiency will raise to over 70%. The aims of this paper consists in the development of complex multifunction materials with nanometric structure and controlled characteristics for special use (civil and or military) with the aid of integrated and flexible technologies for industrial, sectorial and inter-sectorial [1]. Hard alloys based on tungsten (AGW) are this category of metallic materials that have as main compound the tungsten, alloyed with one or many transition metals, like Ni, Cu, Fe, Co etc. Tungsten base hard alloys, composite type have a characteristic embeding structure, biphasic, where the major phase is formed by spheroidal tungsten grains, crystallized in cubic system with centered volume (ccv), embeded in a more ductile matrix, formed by a solid solution soft alloying metal or metals (as a rule from iron group) saturated in tungsten, crystallized in cubic system with centered sides (ccs). This type of alloys have an unique configuration of remarkable properties consisting of: high density, superior mechanical resistance, high ductility, good corrosion resistance, high capacity of radiation absorption, good processing properties, remarkable toughness. The levels of these properties can be modified in very large limits by the help of composition and microstructure, determined in turns by the elaboration technological parameters, depending on the applications of AGW. Some of the potential applicaţions of the system of materials above-mentioned realised by integrated technologies type mechanical alloying – plastic state forming procedures – sintered in micro-wave field, can be:
* application in army field: Different parts devoted to equip systems of weapons like: non-toxic missiles (that do not contain uranium, lead, etc), missiles with controlled behavior at impact, anti-tank ammunition, guiding devices for cruise rockets,etc;
* other fields: Different products for air industry (counterweights to statical and dynamical balance the ailerons for planes and helicopters, mechanisms of control for direction of low rudders, of rotor pallets, devices for radiation barriers allowing attenuation of X rays, disks for computers, magnetic strips, constant magnets, sensors and convectors for solar energy, heads for digital reading, substitutes for diamond powder, inductive compounds, high temperatures resistors, etc.
Keywords
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