####################################################
# Judy Pang <pangj@ornl.gov>
# requesting 6 days, at minimum= days
# beamline 34ID, "Crack tip propagation of Ni3Al-TiC alloys"
####################################################
# top:/home/www/beamtime-requests/req00347.txt
# UNICAT Member Beam Time Request  #347
# created Fri Dec 20 15:46:02 CST 2002
####################################################

beamline:
	34ID

collaboration:
	No

contact:
	pangj@ornl.gov

days:
	6

description:
	Ni3Al-TiC composite is designed for structural and components with stringent requirements because of its high strength, wear resistance and fracture toughness at high temperature. The resistance to fracture is contributed primarily by the constrained plastic deformation of the TiC particles between the rigid Ni3Al grains. Finite element calculation based on Gurson constitutive equations has been reported to account for the fracture mechanism of the system. The essential information to check the validity of these calculations is the stress field, the distributions of hoop stress, hydrostatic stress and microvoid volume fraction in the crack tip field. Fracture toughness measurements using single edge notched bend technique indicated the extent of the crack tip field is ~ 5-10 mm. The submicron spatial resolution of the microbeam facility on 34ID-E will be suitable for the determination of the stress field of both the TiC particles and the Ni3Al phase around the crack tip. The ductile fracture nature of the material facilitates precise controlling of the rate of the crack tip propagation. This is essential as the measurement time required for each crack length will be long.
	
	We propose an experiment to measure the stress distribution in submicron spatial resolution around the crack tip zone of a WC-30 vol% Co alloy. It is estimated measurements over a 5 x 5 x 5 mm3 volume around the crack will take about 1.8 days. Three crack length will be measured for the initial experiment to determine the sensitivity of the stress field with respect to the crack length. Total beam time requested is 6 beam days.

equipment+required:
	ID34-E

experiment:
	Crack tip propagation of Ni3Al-TiC alloys

foreign+nationals:
	Judy Pang

hazards:
	

minimumdays:
	

name:
	Judy Pang

nonmembers:
	Joachim Schneibel, Paul Becher
	Metals %26 Ceramics Division, Oak Ridge National Labs

unacceptable+dates:
	1 February till 10 March


#REMOTE_HOST: pangj2k.ornl.gov
#REMOTE_ADDR: 160.91.156.95
#CONTENT_LENGTH: 2027
#HTTP_REFERER: http://www.uni.aps.anl.gov/unireq.htm
#HTTP_USER_AGENT: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)