YUNUS EMRE AYDOĞDU (3.WEEK)

030050084

Roll bonding:

A brief discussion of the processes that apply severe plastic deformation to a work piece in order to create small grains and thereby increase the strenght is followed by a detailed description of one of these methods: that of accumulative roll bonding. The process is presented first, followed by a detailed discussion of a set of experiments. In that process ultra low carbon steel strips containing 0,002% C were rolled at 500⁰C. Strips of 32 layers were created. The mechanical attributes after Rolling and cooling were examined and the development of edge cracking was monitored. The metal’s yield and tensile strenghts increased by 200-300% while the ductile dropped from pre-rolled value of 75 to 4%. The Rolling process was stopped when cracking of the edges became pronounced. The shear strength of the bond was about 60% of the yield strength in shear. The accumulation of the retained strain after dynamic recovery caused cracking at the edges. A potential industrial application of the accumulative roll bonding process, that of the creation of tailor rolled blanks, is discussed.

(John G. Lenard,Primer of flat rolling, First Edition, Abstract Section)

Abrasive machining:

Abrasive Machining involves material removal by the action of hard, abrasive particles that are usually in the form of a bonded wheel. Grinding is the most important abrasive process. In terms of number of machine tools in use, grinding is the most common of all metalworking operations. Other traditional abrasive processes are generally used as finishing operations, although some abrasive processes are capable of high material removal rates rivaling those of conventional machining operations.

(Mikell P. Groover,Fundamentals of Modern Manifacturing, 4th Editions, pg604)

Hundred Percent Inspection

A Hundred percent inspection is the inspection of every unit of product(procedure, data, operations,etc.).In same cases of 100 percent inspection, the accepts rejects decision will be made not for the entire lot, but for each unit individually, base upon the results of inspection the unit for the quality characteristics concerned. For critical quality characteristics 100 percent inspection or inspection of relatively large samples is usually required to assure the desired quality protection.

(John Langford,Logistics: Principle and Applications, second edition,page 93)

Hierarchical Coding

An alternative form of progressive coding known as hierarchical coding uses a set of successively smaller images that are created by “downsampling” (low-pass filtering and subsampling) the preceding larger image in set is coded with increasing resolution. After the first stage, each lower-resolution image is scaled up to the next resolution (upsampled) and used as a prediction fort he following stage. When the set of images is stacked, it sometimes resembles a pyramid. Consequently this form of codingis also called pyramidal coding.

(William B. Pennebaker, Joan L. Mitchell,JPEG Still image data compression Standard,First edition,pg 79)