Fatih GÜNDÜZ 030060144 (5th week)

Tolerance Analysis:

Computer-aided approaches to tolerance analysis and synthesis fall into several different categories ( Lu et al., 1991). The earliest work focused on conventional tolerances, i.e., manipulation on dimensions, and the analyses of tolerance specifications. More recent work has focused on the issues for both the conventional tolerances and geometric tolerances, i.e., the underlying theory of geometric tolerancing, composition, and proporties such as validity and sufficiency.

(Concurrent design of products, manufacturing processes and systems, Ben Wang, p.75)


Killed steel:

Killed steel is a type of steel from which there is practically no evolution of gas during solidification of the ingot after pouring, because of the complete deoxidation, and formation of pipe in the upper centeral portion of ingot, which is later cut off and discarded. All alloy steels, most low-alloy steels, and many carbon steels are usually killed.
Killled steel is produced by the use of deoxider such as Al and a ferro alloy of Mn or Si. However, calcium silicide and other special deoxidizers are sometimes used.

(Steel heat treatment: metallurgy and technologies, George E. Totten, p.9)


Yield strength:

A stress value obtained graphically that describes no more than a specifed amount of deformation (usually 0.002).Also known as offset Yield strength.

(Essentials of Materials Science and Engineering: SI Edition, Donald R. Askeland,Pradeep P. Fulay, p.183)

Chemical milling:

Chemical milling is a dimensional etching process for metal removal. In working aluminium, it is the preferred method of removing less than 0.125 inch from large, intricate suırface, such as integrally stiffened wing skins for high performance aircraft. Sodium-Hydroxide-base or other suitible alcaline solutions are generally used to chemically mill aluminium. Process is carried out at elevated temperatures. Metal removal (dissolution) is controlled by masking, rayte of immersion, duration of immersion, and composition and temperature of bath.

(Standard aircraft handbook for mechanics and technicians, Larry Reithmaier,Lawrence W. Reithmaier, p.53)