The machining surface localization of free-form blade considering form tolerance

Aerospace blade is the most important part for pneumatic performance with expensive material and cost. Precise NC machining after near-net forming is a trend for aerospace blade machining. If the billet cannot cover the machining surface, the localization is necessary before machining. Because of little machining allowance and various tolerance requirements, free-form surface localization of aerospace blade becomes a puzzle. Traditional free-form surface localization researches focused on finding an appropriate position for design surface to guarantee the enough machining allowance. Different from traditional free-form surface localization research, the form tolerance is considered in the localization optimization. The localization result needs to satisfy the machining allowance and tolerance requirements. To achieve this target, the characteristics of blade modeling and inspection are analyzed. And then, a tolerance constraint is introduced into localization to ensure that the machining surface could satisfy the tolerance requirements. The traditional localization method and the new method considering design tolerance are applied on a compressor blade localization, respectively. From a comparison, the necessity of form tolerance constraint is verified.