Mechanical strength and stress corrosion of new BAR and 7050 alloys that include Zn instead of Cr have been studied and compared with those of 7075 aluminum alloy. Added mechanical strength of new alloys is attributed to finer grain size of 5 to 8 micrometers, however, susceptibility to stress corrosion attack is increased

Adler, P.

Deiasi, R.

English

NASA Technical Reports Server

September 1975	 B75-10200 
NASA TECH BRIEF• 
Marshall Space Flight Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Aluminum Alloys With Improved Strength 
The mechanical strength and stress corrosion 
behavior of two new Al-Mg-Zn alloys have been 
studied and compared with those of 7075 aluminum 
alloy. These are BAR and 7050 alloys that include Zn 
instead of Cr. The results are published in a report. 
Since 7075 alloy is widely used, it is expected that the 
similar, but improved, properties of the Al-Mg-Zn 
alloy will suggest numerous applications. 
One important feature observed with the new alloys 
is their improved mechanical strength in comparison 
with 7075. This added strength is attributed to a finer 
grain size which for the new alloys is from 5 to 8 pm as 
opposed to from 95 to 175 .&m for alloy 7075. 
The reduced grain size increases susceptibility to 
stress corrosion attack. Crack propagation time in the 
new alloys is reduced due to the smaller grain 
boundary precipitate spacing. Overall resistance to 
stress corrosion attack is greatest for the 7075 and 
7050 alloys. However, this depends on the temper of 
the alloy, as some tempers are found to be less 
resistant.
Note: 
Requests for further information may be made in 
writing to: 
Technology Utilization Officer 
Marshall Space Flight Center 
Code ATO1 
Marshall Space Flight Center, Alabama 35812 
Reference: B75-10200 
Patent status: 
NASA has decided not to apply for a patent. 
Source: R. Delasi and P. Adler of
Grumman Aerospace Corp.
(MFS-23239) 
Categories: 04 (Materials) 
06 (Mechanics) 
This document was prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19750000200 2020-03-19T20:27:29+00:00Z


Aluminum alloys with improved strength

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server