Benefiting from advances in feature technology for design and manufacture can not be expected before a formal methodology is established. This paper makes attempt to establish a definition formalism of machining featu...Benefiting from advances in feature technology for design and manufacture can not be expected before a formal methodology is established. This paper makes attempt to establish a definition formalism of machining features in design for manufacturability from two aspects: formal definition and manufacturability analysis. Some definitions for machining feature based upon the selection and sequencing of material removal operations for component in accordance with the design geometry are presented and a framework of feature based design for manufacturability is outlined correspondingly. The proposed scheme contributes to several aspects of feature based CAD/CAM integration, especially to encourage potentially a more generic approach to the automation of design.展开更多
An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition.Epitaxial morphologies of the coating and its microstructural char...An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition.Epitaxial morphologies of the coating and its microstructural characteristics were investigated by means of SEM,XRD and TEM etc.It is observed that the fine column-like dendrites originated from the γ'-particles or γ'-clusters of the DS substrate and are un-continuously coarsened.The β-phase particles precipitate and grow eutectically with the γ-phase.The orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine γ and β phases.展开更多
文摘Benefiting from advances in feature technology for design and manufacture can not be expected before a formal methodology is established. This paper makes attempt to establish a definition formalism of machining features in design for manufacturability from two aspects: formal definition and manufacturability analysis. Some definitions for machining feature based upon the selection and sequencing of material removal operations for component in accordance with the design geometry are presented and a framework of feature based design for manufacturability is outlined correspondingly. The proposed scheme contributes to several aspects of feature based CAD/CAM integration, especially to encourage potentially a more generic approach to the automation of design.
基金Projects(50671116,50901081) supported by the National Natural Science Foundation of China
文摘An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition.Epitaxial morphologies of the coating and its microstructural characteristics were investigated by means of SEM,XRD and TEM etc.It is observed that the fine column-like dendrites originated from the γ'-particles or γ'-clusters of the DS substrate and are un-continuously coarsened.The β-phase particles precipitate and grow eutectically with the γ-phase.The orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine γ and β phases.
