Study On Preparation And Performance Of Fe/Al Reactive Material Liner

When impact the target by a high speed, Fe/Al reactive materials react vigorously with abundant heat given out. The liner prepared by Fe/Al reactive materials has controllable density and high reaction energy, which has potential to make high penetration depth and large hole. However, the energy release mechanism of Fe/Al reactive materials in penetration is not clear. The purpose of this paper is to prepare a reactive material liner with high reaction energy, and study the energy release mechanism of penetration to support the development of the large hole liner. The main research contents are as follows:Powder metallurgy was used to prepare reactive materials, which had quality ratios of Fe:Al are 3:7, 4:6 and 5:5 respectively. Effects of sintering temperature on the microstructures of materials were also studied in this paper. The results show that: when sintered at the low temperature of 510?, there are only diffusion phenomenons and trace amounts of solid phase reaction in materials. When the sintering temperatures are raised, the reactive materials begin to generate metal compound reactions partly, and intermetallic compounds are generated. When the sintering temperatures increase to 590?, there are adequate metal compound reactions in reactive materials. With the Fe contents increase, the critical temperature(Fe+Al?FexA1y) is improved slightly.To predict the reaction energy release characteristics, thermal analyses of Fe/Al reactive materials were carried out, combined with theoretical calculation. And the reaction behaviors of reactive materials at different impact conditions were studied. The results show that: oxidation reaction heat(30.92KJ/g) is much greater than that of the chemical reaction between iron and aluminum(Fe2A15: 760J/g). The reaction heat of compacts decrease gradually with the component ratio change ordinal from 4:6 to 5:5, 3:7 in the anaerobic environment, and compact with the component ratio of 4:6 has the greatest reaction heat:-589.8J/g. In the Split Hopkinson Bar test(·e =10000s-1) and high speed penetration test(800m/s), there aren't any reactions in 3/7-510? materials, so the reactive materials have excellent insensitivity.The mechanical properties of Fe/Al reactive materials were studied, and the results showed that: after 510? sintering, the static compressive strength of 3/7 reactive material is 176.6MPa, only 2.4% greater than that of green compact, while the plasticity increase greatly. With the Fe contents increase from 30% to 50%, the static compressive strengths of sintered samples increased by 6.2%, while the tensile strengths increase first and then decrease. 4/6-510? sample has the maximum tensile strength: 104.8MPa. Because of the combined effects of pores and Fe contents on compressive strength, the dynamic compressive strengths of the samples with different component ratios are little different, and between 256~261MPa. When the sintering temperature increases to 590 ?, intermetallic compounds are generated in reactive materials, which makes the static compressive strengths of the materials increase to 295.2MPa, the dynamic compressive strengths increase to 345 MPa, and plasticitiy decreases.Under different impact conditions, static penetration tests of Fe/Al reactive material liners with different component ratios and organization strctures. The energy release mechanism of penetration was explored by analyses of worked targets, reclaim products and energy calculations. The results showed that: the target impacted by the reactive material liner will produce a large hole and the oxidation and combination reactions will be caused, which release a large amount of energy. The main factor that affect the reaction energy of the liner is the contents of oxidized Al. The more Al oxidizes, the more energy releases. Liner(32mm diameter hemispherical liner) with a ratio of 4/6 possesses the maximum amount of total released energy: 21.14 KJ, which is close to the total released energy of pure aluminum liner(21.52KJ), but the liner density increased by 23%, which provides a key condition for achieving a high penetration depth and a large hole at the same time. A appropriate amount of intermetallic compounds in reactive materials contribute to improving the degree of the oxidation of Al, and thereby improve the reaction energy. The fiercer the impact of penetration jet to target is, the more the energy releases, which because the reactive of materials reaction is more complete. High speed jet impact the middle clapboard can cause secondary reaction after pierce through the first level target, making the energy increase 2.2 times.