| Summary: | 碩士 === 國立海洋大學 === 材料工程研究所 === 88 === A Study on the Fabrication and Characterization of High Performance Ballistic Metallic Materials
Abstract
The composition, performance and design of the ballistic or protection materials are regarded as high secrecy for each country, therefore, the papers or documentations about armor application and ballistic evaluation are seldom reported in journal or publication. Rolled homogeneous armor (RHA) steels are the most common materials used for armor protection at present. In 1985, a new alloy called improved rolled homogeneous armor (IRHA) was successfully developed in USA as well. In fact, both RHA and IRHA are widely used for armor, however, technical data related to the fabrication and structure design are purposely protected. Thus, details concerning alloy design, material melting, production, hot working, microstructure control and heating treatment are remained unknown for structure design or ballistic evaluations.
In this study, the influence of processing and microstructure of RHA and IRHA was carried out and investigated for the first time in Taiwan/ ROC. In addition, the comparison in mechanical behavior and ballistic performance (between a purchased RHA from oversea and the alloys prepared in present work) was systematically made.
The experimental results showed that the RHA and IRHA are homogeneous and clean during vacuum induction melting (VIM) and vacuum arc refine (VAR) process. Both purchased and melt ingots were hot-rolled down to 4 mm in thickness, followed by heat treatment to receive various hardness in sheet. Then, the mechanical property、 microstructure observation and a ballistic limit test by using of 44 grain fragment simulating projectile (FSP) were performed. It is demonstrated that the IRHA has a superior mechanical property、good impact toughness and better ballistic resistance than those of RHA when the hardness of IRHA is controlled between HRc 40 to 50. Based on the experiment results, a number of information concerning the alloy design、the parameter of the melting、rolling and heat treatment are obtained and analyzed, which are quite helpful for the engineering design and mass production in future work.
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