Profile Measurement Based on Focus Variation Method for Geometrical Defect Evaluation: A Case Study of Cold Forged Propeller Blade

Abstract

Geometrical defect is one of the main problems that will affect performance and perfect mating of produced parts. Coordinate measurement machine (CMM) is commonly used for the measurement, but the use of this machine is limited because of the small size and complexity of the component or features. This study aims to evaluate the defect that occurs on an AA6061 cold forging blade produced using cold forging process based on profile measurement technique. A systematic approach based on focus variation was proposed to evaluate two features, that is, roundness error and twist deviation. The profile was obtained with the use of InfiniteFocus Alicona 3D surface measurement system. Specific algorithms were developed for different cases as the evaluation of the features is discrete and the results were validated.

An Adaptive Hybrid Sampling Method for Free-Form Surfaces Based on Geodesic Distance

“…This kind of part has a complex structure and large size, which also puts forward higher requirements for the dexterity and space of measuring equipment. The geometric measurement of a free-form surface can adopt a contact or non-contact measurement [ 2 ]. In the process of the geometric measurement of a free-form surface, the geometric error can be evaluated from two aspects: measurement accuracy and measurement efficiency.…”

Smart Coordinate Measuring Machine (CMM) Inspection for Turbine Guide Vanes with Trend Line and Geometric Profile Tolerance

“…Well-written CMM inspection programs can provide reliable and repeatable measure processes for a large set of components and CAD based sampling and point reduction is a very good start for CMM path programming. Abdullah [6] investigated blade geometry discontinuity, such as small diameter holes or inconsistent depths, demonstrating that a CMM test may not reveal any problems or provide inconsistent results. A possible solution might be non-destructive testing that can identify the occurrence of these flaws before CMM inspection and properly set tolerance boundaries can result in disregard for small, identified flaws.…”