Accession Number : AD0431856


Title :   ELEVATED TEMPERATURE TESTS OF CHROMIUM - TITANIUM - SILICON COATED F48 COLUMBIUM ALLOY BOLT AND NUT,


Corporate Author : MCDONNELL AIRCRAFT CORP ST LOUIS MO


Personal Author(s) : Wilcox,Robert R


Report Date : 10 Mar 1964


Pagination or Media Count : 8


Abstract : A F-48 Columbium alloy bolt and nut was subjected to four 1/2 hour cycles of exposure to 2500F and cooled to room temperature. Prior to, and after each exposure the bolt and nut was weighed to .0001 grams and the weight gain determined. Following thermal cycling the bolt and nut was cross sectioned and metallographically examined, photographed, and coating thickness measured on the bolt shank and thread areas. Metallographic examination showed an equiaxed grain structure, resulting from recrystallization. Recrystallization began to replace the wrought structure, characteristic of the bolt before thermal cycling. Visual examination of the bolt and nut after the temperature exposures exhibited blemishes of chromium oxides on both bolt and nut. (Author)


Descriptors :   *BOLTS , *LOCKING FASTENER DEVICES , NIOBIUM ALLOYS , NIOBIUM ALLOYS , HIGH TEMPERATURE , SCIENTIFIC RESEARCH , COATINGS , CHROMIUM , TITANIUM , SILICON , VAPOR PLATING , MICROSTRUCTURE , PHOTOMICROGRAPHY


Distribution Statement : APPROVED FOR PUBLIC RELEASE