Solid Freeform Fabrication of Functionally Graded Materials
Solid Freeform Fabrication of Functionally Graded Materials
Abstract:
Functionally Graded Materials (FGMs) have a wide range of potential commercial applications which consist of components requiring wear-resistant surfaces such as engine components, rocket nozzle and so forth [1]. Solid freeform fabrication (SFF), especially Freeze-form Extrusion Fabrication (FEF) technology, an economical method feasible for grading among many compatible plastic, ceramic and metal materials combinations. In this paper, I describe how FEF method build Al2O3/ZrO2 graded parts and it used to test the graded material compositions by energy dispersive spectroscopy (EDS) after drying, binder burnout and sintering these parts. While ZrC/W graded test bars were fabricated and used to test mechanical properties and microstructures.
Keywords: Functionally graded materials, Solid freeform fabrication, Extrusion
1 Introduction Fabrication of functionally graded materials (FGMs) are materials that are produced with multiple materials in graded fashion taking advantage of complementary material properties. In addition, ceramic materials are often used in high-temperature applications for their superior heat resistance. However, pure ceramic materials are hard to use in high-stress environments and are often difficult to use in building complex geometries by using traditional processes due to its poor fracture toughness [1]. Thus, the metal-ceramic or ceramic-ceramic material is desirable. To prepare FGMs for objects with complex shape and three-dimensional (3D) compositional gradients, solid freeform fabrication (SFF) methods would be required. Traditional manufacturing methods of FGMs objects include slip casting, tape casting, thermal spraying, vapor deposition; While shortcomings of these techniques include the extensive use of toxic organic solvents, long fabrication time, low repeatability, irregularly shaped pores, and thin structures [2,3]. Most importantly, these
Abstract:
Functionally Graded Materials (FGMs) have a wide range of potential commercial applications which consist of components requiring wear-resistant surfaces such as engine components, rocket nozzle and so forth [1]. Solid freeform fabrication (SFF), especially Freeze-form Extrusion Fabrication (FEF) technology, an economical method feasible for grading among many compatible plastic, ceramic and metal materials combinations. In this paper, I describe how FEF method build Al2O3/ZrO2 graded parts and it used to test the graded material compositions by energy dispersive spectroscopy (EDS) after drying, binder burnout and sintering these parts. While ZrC/W graded test bars were fabricated and used to test mechanical properties and microstructures.
Keywords: Functionally graded materials, Solid freeform fabrication, Extrusion
1 Introduction Fabrication of functionally graded materials (FGMs) are materials that are produced with multiple materials in graded fashion taking advantage of complementary material properties. In addition, ceramic materials are often used in high-temperature applications for their superior heat resistance. However, pure ceramic materials are hard to use in high-stress environments and are often difficult to use in building complex geometries by using traditional processes due to its poor fracture toughness [1]. Thus, the metal-ceramic or ceramic-ceramic material is desirable. To prepare FGMs for objects with complex shape and three-dimensional (3D) compositional gradients, solid freeform fabrication (SFF) methods would be required. Traditional manufacturing methods of FGMs objects include slip casting, tape casting, thermal spraying, vapor deposition; While shortcomings of these techniques include the extensive use of toxic organic solvents, long fabrication time, low repeatability, irregularly shaped pores, and thin structures [2,3]. Most importantly, these
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