Richard A. Haber

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Boron carbide is characterized by a unique combination of properties that make it a material of choice for a wide range of engineering applications. Boron carbide is used in refractory applications due to its high melting point and thermal stability; it is used as abrasive powders and coatings due to its extreme abrasion resistance; it excels in ballistic(More)
Single crystal piezoelectric composite transducers including 75 MHz PC-MUT (piezoelectric composite micromachined ultrasound transducers), diced 10 MHz and 15 MHz 1-3 composite transducers were successfully demonstrated with broad bandwidth and high sensitivity. In this paper, the design, fabrication and characterization of composite transducers are(More)
Auto-granulation is the growth of particle clusters within a dry, fine powder bed due to the bulk powder cohesion. This clustering occurs without the addition of any binder to the system due to simple agitation of a powder, such as during storage or handling. For this reason, it is important in powder processing to be able to characterize this behavior. In(More)
Modeling of Gas Phase Transport and Composition Evolution during the Initial Stage Sintering of Boron Carbide with Carbon Additions M. A. Rossi, M. J. Matthewson, A. Kaza, D. Niesz, R. A. Haber Department of Materials Science and Engineering Rutgers, The State University of New Jersey 607 Taylor Road, Piscataway, New Jersey 08854 Abstract Densification of 4(More)
Recent observations of planar defects in boron carbide have been shown to deviate from perfect mirror symmetry and are referred to as "asymmetric twins." Here, we demonstrate that these asymmetric twins are really phase boundaries that form in stoichiometric B(4)C (i.e., B(12)C(3)) but not in B(13)C(2). TEM observations and ab initio simulations have been(More)
The theoretical strength of a material is the minimum stress to deform or fracture the perfect single crystal material that has no defects. This theoretical strength is considered as an upper bound on the attainable strength for a real crystal. In contradiction to this expectation, we use quantum mechanics (QM) simulations to show that for the boron carbide(More)
High density is a critical acceptance criterion for armor ceramics. Quantifying the difference in density between what would be considered to be a “good” or “bad” region is complicated. As density is reduced from theoretical, does this infer the presence of defects? The minimum acceptable density that ensures favorable ballistic performance is unknown. This(More)
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