The Three-Dimension Evaluation Of Casting Surface Roughness On Basis Of Digital Image Technology

The surface roughness is one of important parameters of surface quality evaluation. Casting surface was not attached importance in the past because it is too rough to be evaluated. Just for the reason of the complexity of the casting surface, the existing two-dimension evaluation standard does not consist of parameters relating to micro roughness space and profile characteristics. Technicians in some colleges and research institutes evaluated casting surface roughness used traditional comparator and probe instruments, but these traditional methods either was low in testing accuracy or could not be used in spot testing. With the development of science and technology, the three-dimension measurement is making a figure in evaluating surface roughness. In allusion to the particularity of the casting surface roughness, the author adopts digital image processing and recognizing technology of computer to gather the pictures of examined casting profile and change the pictures into gray level images. A set of three-dimension parameters suitable for measuring and relevant algorithm were established in the paper. The surface roughness of casting can be put out finally by reading pictures and calculating parameters based on computer. Although these experiments are all exploratory, the feasibility of three-dimension evaluation of casting surface roughness based on digital imaging technology was approved. The experimental work has laid a foundation for establishing scientific standard of three-dimension evaluation of casting surface roughness and developing relevant testing system in the future.