Date of Award

Spring 2002

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Mechanical Engineering - (Ph.D.)

Department

Mechanical Engineering

First Advisor

E. S. Geskin

Second Advisor

Bernard Koplik

Third Advisor

R. S. Sodhi

Fourth Advisor

Zhiming Ji

Fifth Advisor

Sanchoy K. Das

Abstract

The objective of the proposed work is to acquire knowledge needed for the development and deployment of manufacturing processes utilizing the enormous technological potential of water ice. Material removal by blasting with ice media such as particles, pellets and slugs was investigated. The ice media was accelerated by entrainment in a fluid stream (air, steam, liquid water, supercritical C02), impact of rotating blades, fluid expansion, etc. The ice-airjet has to replace sand blasting and the ice-waterjet has to replace the abrasive waterjet. Based on these results, technical approaches for surface processing and machining will be improved. A primary advantage of the ice media is movement toward more complete pollution prevention. With this technique, it is possible to eliminate both contamination of the substrate and generation of contaminated waste streams. In addition to the obvious environmental benefits, use of ice media has improved a number of key operational techniques, such as cleaning, decoating, polishing, deburring, drilling, cutting, etc.

Production of ice media "just-in-time" at minimal environmental cost constitutes another advantage of ice-based technologies. A key objective of this research is to improve ice blasting so that it is not just feasible, but also technologically and economically efficient. An understanding of process physics and its application to the manufacturing operations are necessary in order to attain this objective. The feasibility and effectiveness of other than blasting ice-based technologies, such as precision temperature control, mixing, forming, etc. was also investigated.

The principal issue in the use of the ice abrasives is formation of the ice particles. Two technologies of the particles formation were investigated. One of these technologies involves crushing and subsequent grinding of ice blocks. It is applicable at conditions when ice is readily available, for example at Arctic. Another process involved integration of water freezing and decomposition of the generated ice. It was shown that the size distribution of the particles is determined by the rate of the water supply and cooling conditions.

The results of the experiments were used to suggest a technology for surface processing using ice powder. A process for formation of the powder of brittle materials was also discussed.

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