Accession Number : AD0278277

Title :   TUNGSTEN AND ROCKET MOTORS

Corporate Author : STANFORD RESEARCH INST MENLO PARK CALIF

Personal Author(s) : GORDON,G.M. ; BROWN,D.A.

Report Date : 31 MAY 1962

Pagination or Media Count : 1

Abstract : Thermal shock and erosion characteristics of tungsten were studied under simulated solid propellant nozzle conditions. The erosion of tungsten was investigated in a high velocity plasma as a function of exhaust component (CO2 and Al2O3), temperature (2800 to 3350 C), component flux, and type of tungsten. The tungsten erosion mechanism in CO2 was found to be the formation and volatilization of tungsten oxide. The erosion rate was principally dependent upon the incident CO2 gas flux and relatively insensitive to surface temperature and type of tungsten. Thermal shock tests in a specially constructed apparatus were performed on a series of hollow tungsten and ceramic cylinders. A method for determining the maximum thermal stresses was devised which requires only measuring the outer surface temperature and strain, and a knowledge of the elastic constants up to the ductile-brittle transition temperature of the tungsten cylinder. A relationship between rate of rise of mean specimen temperature, outer surface strain rate, and specimen dimensions was developed and a preliminary experimental verification was obtained. Thermal shock cracks were produced and crack orientation was correlated with the ratio of cylinder height to outside diameter. (Author)

Descriptors :   ELASTIC PROPERTIES, EROSION, EXHAUST GASES, FRACTURE (MECHANICS), GAS FLOW, HIGH TEMPERATURE, PLASMA JETS, ROCKET ENGINES, SIMULATION, SOLID ROCKET PROPELLANTS, STRESSES, TEMPERATURE, TENSILE PROPERTIES, TEST METHODS, THERMAL STRESSES

Distribution Statement : APPROVED FOR PUBLIC RELEASE