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.

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 September 16, 2014 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 September 16, 2014).

Share This



More Matter & Energy News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) — MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com
Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) — Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com
Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Reuters - US Online Video (Sep. 15, 2014) — New York officials unveil subway tunnels that were refurbished after Superstorm Sandy. Nathan Frandino reports. Video provided by Reuters
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:
from the past week

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