Roughing an impeller: A review

Impeller is a rotating device, which transforms fluid flow from axial to radial direction. It consists of several identical, twisted blades with ruled surfaces, which are attached to a hub surface. Commonly, impeller needs high-speed rotation in order to increase the pressure flow of a pump or turbine engine. High machining accuracy is vital in producing an impeller. In this sense, there are many issues in producing a high quality impeller. Not enough information has been provided to guide new researchers in this field in the meantime. To overcome this problem, therefore, this paper reviews existing researches associated with impeller machining, focusing on the roughing strategies. An extensive study covers the literature from 1970 to 2013, mapping out research issues regarding roughing strategy in details. This paper classifies the impeller roughing strategy issues in a chronological order according to the main idea and issues. A clear analysis of machining strategies provided by dividing them into 4 categories; (1) improving machining time, (2) avoiding tool collisions, (3) undercut avoidance, and (4) chatter avoidance. Critics on the existing work and research trends reported as discussions and conclusion.