In ball milling metal powders to submicron size, various salts are more effective as grinding aids than conventional surfactants. Absolute ethyl alcohol is used as the grinding liquid

Quatinetz, M.

Schafer, R. J.

English

NASA Technical Reports Server

May 1966	 Brief 66-10221 
NASA TECH BRIEF	
A. 
>..::::<.••:.::.•::::::::::. .................... fl +.<	 ... 	 w,Wttt4#to 
NASA Tech Briefs are issued to summarize specific innovations derived from the U. S. space 
program and to encourage their commercial application. Copies are available to the public from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Submicron Metal Powders Produced by Ball Milling with Grinding Aids 
The problem: 
To produce metal powders of an average particle 
size of less than 1 micron by ball milling of coarser 
powders with selected grinding aids. Some of the 
variables associated with ball milling are the size, 
material, and construction of the grinding container, 
the nature and amount of the grinding material and 
the material to be ground, the nature and amount of 
the grinding aid and liquid used, and the grinding 
time. In all ball milling, agglomeration due to weld-
ing or flocculation of the particles limits the ultimate 
particle size that can be obtained. Greater difficulty 
is often encountered in the grinding of ductile metals 
(e.g., copper, nickel, silver), because the particles 
have a greater tendency to weld together than those 
of brittle or friable metals. 
The solution: 
In experiments with powdered nickel, iron, chro-
mium, silver, and copper, obtained from commercial 
sources, various salts (with different ion size, valence, 
and polarizability) were generally found to be more 
effective than conventional surfactants as aids in ball-
milling the metals into powders having an average 
particle size down to 0.1 micron. Among the salts 
found to be most effective were cerium nitrate, 
aluminum nitrate, sodium dichromate, potassium 
ferricyanide, potassium ferrocyanide, and sodium 
pyrophosphate, with absolute ethyl alcohol as the 
grinding liquid. 
How it's done: 
Specific amounts of the metal powders with various 
grinding liquids (including water, absolute ethyl
alcohol, cyclohexane, n-heptane, and methylene 
chloride), various salts, and surfactants were ground 
with stainless steel balls in a stainless steel milling 
jar for 2 to 15 days. The grinding effectiveness was 
determined by measuring the particle sizes of samples 
taken at various times. Three groups of ball-milling 
experiments were run, one in which the grinding aid 
(salt or surfactant) was varied, a second in which 
the grinding fluid was varied, and a third in which 
the material being ground was varied. A total of 22 
salts, 11 surfactants, 5 grinding fluids, and 11 metal 
powders (consisting of 5 different metals) were used. 
Most of the experiments consisted in varying the 
grinding aid employed and were performed using 
nickel powder (Inco carbonyl grade B), having an 
initial particle size of 2.5 microns, as the material 
being ground and absolute ethyl alcohol as the grind-
ing fluid. 
Note: 
Further information concerning this innovation is 
given in NASA TN D-879, "The Production of Sub-
micron Metal Powders By Ball Milling With Grinding 
Aids" by Max Quatinetz, Robert J. Schafer, and 
Charles R. Smeal, March 1962, available from the 
Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia, 22151. Inquiries 
may also be directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio, 44135 
Reference: B66-10221 
Adsk	 (continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19660000220 2020-03-11T17:32:32+00:00Z
Patent status: 
This is the invention of NASA employees, and 
U.S. Patent No. 3090567 has been issued to them. 
Inquiries about obtaining license rights for its com-
mercial development should be addressed to the 
inventors, Mr. Max Quatinetz and Mr. Robert J. 
Schafer, at Lewis Research Center. 
Source: Lewis-188 
Brief 66-10221	 Category 03


Submicron metal powders produced by ball milling with grinding aids

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server