Featured Research

from universities, journals, and other organizations

Hollow Spheres Made Of Metal

Date:
October 13, 2009
Source:
Fraunhofer-Gesellschaft
Summary:
Producing metallic hollow spheres is complicated: It has not yet been possible to make the small sizes required for new high-tech applications. Now for the first time researchers have manufactured ground hollow spheres measuring just two to ten millimeters.

Hollow spheres made of ground steel, measuring just two to ten millimeters.
Credit: Copyright Fraunhofer IFAM

Producing metallic hollow spheres is complicated: It has not yet been possible to make the small sizes required for new high-tech applications. Now for the first time researchers have manufactured ground hollow spheres measuring just two to ten millimeters.

Related Articles


New drive technologies combined with lighter and stronger materials will make the airplanes and automobiles of the future more fuel-efficient. But a number of technical details need to be resolved first. Magnetic ball valves are one example – for them to react extremely quickly, the balls must be as light as possible, and the same applies to rapidly moving bearings. Hollow spheres made of steel represent a solution.

Researchers at the Fraunhofer Institute for Manufacturing and Advanced Materials IFAM in Dresden working in cooperation with hollomet GmbH Dresden have created the technology for the manufacture of rapidly reacting ball valves and bearings. “In an injection valve the movement of a ball causes the valve to open and close. The lighter the ball, the quicker it moves,” explains Dr.-Ing. Hartmut Gφhler, project manager at the IFAM. Until now it has only been possible to produce balls of this size as solid spheres, but a solid body is relatively heavy and therefore reacts slowly in a ball valve. “For the first time we’ve been able to produce metal hollow spheres in the required diameter of just two to ten millimeters. The hollow spheres are 40 to 70 percent lighter than solid ones.”

The process starts with polystyrene balls which are lifted up and held by an air current over a fluidized bed while a suspension consisting of metal powder and binder is sprayed onto them. When the metal layer on the balls is thick enough, heat treatment begins, in which all the organic components, the polystyrene and the binder evaporate. The residual materials are gaseous and escape through the pores in the metal layer. A fragile ball of metal remains. This is now sintered at just below melting temperature, and the metal powder granules bind together, forming a hard and cohesive shell. The sphere is now stable enough to be ground in a machine, but the pressure must not be too high as otherwise the hollow body will deform. The wall thickness can be set to between a few tenths of a millimeter and one millimeter.

Gφhler sees applications for the technique wherever a low mass inertia is required. “Hollow spheres will create applications which have not been possible up to now,” Gφhler states. The scientists have already produced ground spheres made of steel, other metals such as titanium and various alloys are envisaged for the future.


Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.


Cite This Page:

Fraunhofer-Gesellschaft. "Hollow Spheres Made Of Metal." ScienceDaily. ScienceDaily, 13 October 2009. <www.sciencedaily.com/releases/2009/10/091012095709.htm>.
Fraunhofer-Gesellschaft. (2009, October 13). Hollow Spheres Made Of Metal. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2009/10/091012095709.htm
Fraunhofer-Gesellschaft. "Hollow Spheres Made Of Metal." ScienceDaily. www.sciencedaily.com/releases/2009/10/091012095709.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gas Production Cut on Earthquake Fears

Gas Production Cut on Earthquake Fears

Reuters - Business Video Online (Mar. 5, 2015) — The Dutch government has cut production at Europe&apos;s largest gas field in Groningen amid concerns over earthquakes which are damaging local churches. As Amy Pollock reports the decision - largely politically-motivated - could have big economic conseqeunces. Video provided by Reuters
Powered by NewsLook.com
Star Wars-Inspired Prototype Creates Holographic Display

Star Wars-Inspired Prototype Creates Holographic Display

Reuters - Innovations Video Online (Mar. 5, 2015) — A prototype holographic display named Leia - after the Star Wars princess who appeared in holographic form asking Obi-Wan Kenobu for help - is demonstrated at the Mobile World Congress in Barcelona. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
IKEA and Samsung Launch Embedded Wireless Charging Range

IKEA and Samsung Launch Embedded Wireless Charging Range

Reuters - Innovations Video Online (Mar. 5, 2015) — Samsung and IKEA hope their new embedded wireless charging products, launched at Barcelona&apos;s Mobile World Congress, will tempt consumers eager for plugless power. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Samsung Unveils $30,000 'Dream Doghouse'

Samsung Unveils $30,000 'Dream Doghouse'

Buzz60 (Mar. 5, 2015) — On display at the Crufts dog show in England, the &apos;dog kennel of the future&apos; comes with features like a doggie treadmill and Samsung tablet. Mike Janela (@mikejanela) has more. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins