Analysis of Pershing II Reentry Vehicle (RV) Control Ring Castings
Abstract
A comparative material analysis was performed on two PERSHING II RV control rings with reported differences in tensile properties and percent elongation. Both RV control rings were characterized by tensile tests, chemical analysis, fracture toughness tests, and metallography. The comparative analysis proved that the two examined RV rings were equivalent, though contractor tensile coupon tests showed otherwise. The average properties of the RV control ring were; 37.25 ksi (256.6 MPa) ultimate strength, 32.65 ksi (225 MPa) yield strength, 5.7 percent elongation, and 15.505 ksi sq.root (16.55 MPa sq.root) KIC fracture toughness. The RV rings are fabricated from A356-T6 aluminum. Analysis of cast tensile coupon specimens was also performed to determine the major reason for large differences in percent elongation resulting from quality control tensile tests. Electron microscopy and metallography revealed that large casting flaws (eutectic silicon segregation) had occurred in most tensile specimens with low percent elongation. Therefore, inaccurate (low) mechanical property and percent elongation data resulted from these tensile specimens with casting flaws. Aluminum, Eutectic silicon, Tensile strength, Elongation, Fracture toughness.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1988
- Accession Number
- ADA201548
Entities
People
- Albert S. Ingram
Organizations
- United States Army Aviation and Missile Command