Featured Research

from universities, journals, and other organizations

Cast Iron Graphite Shape, Fine Structure Are Keys To Cheaper, Faster Machining

Date:
June 8, 1999
Source:
Penn State
Summary:
Penn State engineers have shown that the shape of the graphite flakes, as well as the microstructure, in cast irons influence the amount of cracking and chipping that occurs during the machining process used to make gears, engine blocks, and other finished parts.

University Park, Pa. --- Penn State engineers have shown that the shape of the graphite flakes, as well as the microstructure, in cast irons influence the amount of cracking and chipping that occurs during the machining process used to make gears, engine blocks, and other finished parts.

Dr. Robert C. Voigt, professor of industrial engineering, says, "If you can increase the life of a cutting tool or reduce product breakage during manufacturing by using more consistently machinable cast iron, costs will go down. We think we have the first strong evidence that connects microstructure and graphite particle shape with machinability."

Penn State researchers detailed their study in a paper, "Influence of Graphite Morphology and Matrix Structure on Chip Formation During Machining of Gray Cast Irons," presented at the American Foundryman's Society meeting in St. Louis, Mo. in March.

The authors are Dr. Ruben Marwanga, research assistant and Fulbright Fellow; Voigt, and Dr. Paul H. Cohen, professor of industrial and manufacturing engineering.

The group looked at commercial grades of gray and ductile cast iron, using slow speed machining as well as a high-speed quick-stop-device. They used a high magnification video camera system to record the process and then examined the machined samples with optical and scanning electron microscopes.

Magnified 50 times in the research videotapes, the surface of the cutting tools resembles a plow turning soil as it machines the surface of the cast iron sample. The tapes clearly demonstrate that cracking occurs along the graphite flakes and that severe deformation occurs in the surrounding matrix structure. The longer the graphite flakes, the longer the fracture distance ahead of and below the cutting tool.

The research also revealed that fine free graphite exists at the tool/chip interface of all gray irons and performs an important lubrication role. The graphite at the interface forms a thin solid film that separates the tool from the work and reduces strain and friction. The result is lower tool/sample interface temperatures and enhanced machinability.

The researchers also found that the type of matrix or fine microstructure in which the graphite was embedded played a role in machinability. They examined typical cast iron microstructures, including ferrite, ferrite/pearlite, and fully pearlite, and found that the higher the amount of ferrite, the easier it is to machine.

Gray irons have different machining characteristics than ductile irons and leaded steels. Ductile irons are more plastic and form longer chips than gray irons. Leaded steels show a much higher ductility than ductile irons, longer deformation distances and the formation of continuous chips during machining.

Voigt notes that the researchers are currently forming a consortium of companies to further examine the role of graphite and structure on cast iron machinability. Their goal is a consistently machinable cast iron that will provide better performance when machined rapidly by automated machining cells. The research was supported, in part, by grants from Dura Bar Division of Wells Manufacturing Co., Woodstock, Ill.


Story Source:

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


Cite This Page:

Penn State. "Cast Iron Graphite Shape, Fine Structure Are Keys To Cheaper, Faster Machining." ScienceDaily. ScienceDaily, 8 June 1999. <www.sciencedaily.com/releases/1999/06/990608071430.htm>.
Penn State. (1999, June 8). Cast Iron Graphite Shape, Fine Structure Are Keys To Cheaper, Faster Machining. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/1999/06/990608071430.htm
Penn State. "Cast Iron Graphite Shape, Fine Structure Are Keys To Cheaper, Faster Machining." ScienceDaily. www.sciencedaily.com/releases/1999/06/990608071430.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
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