SEDL / STP / STP1111-EB / STP17766S

Macro- and Microreactions in Mechanical-Impact Tests of Aluminum Alloys

Reed, RP
consultantMaterials Research Engineerphysical scientistphysicist, National Institute of Standards and Technology (NIST)NISTNISTNIST,

McCowan, CN
consultantMaterials Research Engineerphysical scientistphysicist, National Institute of Standards and Technology (NIST)NISTNISTNIST,

McColskey, JD
consultantMaterials Research Engineerphysical scientistphysicist, National Institute of Standards and Technology (NIST)NISTNISTNIST,

Simon, NJ
consultantMaterials Research Engineerphysical scientistphysicist, National Institute of Standards and Technology (NIST)NISTNISTNIST,

Pages: 20    Published: Jan 1991

Download this paper for $25 PDF (980K)          View License Agreement
Abstract

Open-cup and pressurized mechanical-impact tests have been conducted at the NASA White Sands Test Facility (WSTF) on selected tempers of Al-Li alloys (2090, 8090, WL049), and Al alloy 2219. Both liquid (LOX) and gaseous (GOX) oxygen environments were used and pressure and drop height (potential energy) were varied in each environment. Reactions were observed in all alloys and tempers on both sides of the specimens. Reaction sizes, morphologies, and locations were characterized using a magnifying glass (2X power), a light microscope (5 to 100X), and a scanning electron microscope (100 to 3000X). Photomicrographs of various types of macro- and microreactions are presented and discussed. The variety of sizes of reactions poses a serious problem for the definition of a reaction in standards documents for LOX and GOX mechanical-impact qualification testing. This dilemma is discussed.