Development of Laminate Metal Matrix Composites.
Abstract
Boron carbide films were condensed under varying conditions onto titanium, tantalum and aluminum surfaces by vacuum deposition to examine the effect of deposition variables on the laminar tensile strength of the film. Tensile strength determined directly on free film sections as well as by comparative methods, generally was found to increase slightly with deposition temperature in the range 350 to 730C and to vary inversely with deposit thickness. In the B4C-Ti system, an interfacial reaction above 730C was observed which appeared to reduce film strength. Under conditions to minimize residual stresses in the deposit, maximum tensile strength values for boron carbide of 193 ksi on Ta, 131 ksi on Ti and 60 ksi on Al were obtained. The relatively low strength for boron carbide deposited on Al was attributed to microcrack formation induced by the large thermal expansion differential. Further increases in film strength were noted after annealing at 1250-1300C. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1969
- Accession Number
- AD0864269
Entities
People
- G. E. Padawer
- M. J. Hordon