Powder Injection Moulding (PIM) of Dissimilar Materials and Complex Internal Features

Transcription

1 Powder Injection Moulding (PIM) of Dissimilar Materials and Complex Internal Features Li Tao, Scientist II Metal&Ceramic Team, Forming Technology Group, (SIMTech) Tel:

2 Outline PIM process and application PIM research areas in SIMTech Over-PIM for dissimilar materials Over-PIM for complex internal features Summary 2

3 Products by PIM SIMTech Variety of materials Complexity Precise dimension ocus-medical-plant-tour-metalinjection-molding-smiles 3

4 PIM Process PIM combines the flexibility and design of plastic injection molding with the excellent properties of metals and ceramics produced from powders. 4

5 Technology Comparison Press and Sinter Metal Injection Molding Die Casting Machining Investment Casting PIM is a cost effective mass production process to produce small complex metal and ceramic components with net or near-net shapes. 5

6 Advantages and Applications 6

7 PIM Market Firearms Medical Consumer Aerospace Automotive Electronics Annual Sales of PIM and MIM 7

8 Research Focuses at SIMTech Over-PIM Sintering shrinkage compatibility Binder system for big components Multi-functional composite Micro-PIM complex internal feature Sacrificial core material to create internal channels Binder system for micro features and micro parts Shape maintenance for small feature with high AR Micro component Micro features PIM for Advanced Materials Microstructure development for sintering of fine powders Binder system for exotic materials Impurity control in the sintered components Titanium alloy 1mm Translucent ceramic Nickel-base superalloy Relationship between materials, processing and properties. 8

9 Over-PIM Originated from the two-color plastic injection molding Rotational mold and two injection units Over-PIM process Double barrel injection molding machine Feedstock Preparation Over-injection molding Debinding Sintering Over-PIM application: Dissimilar materials (multi-functional component, composite component) Internal features 9

10 Over-PIM of Dissimilar Materials Combination I: Fe2Ni(I)/316L(O) Sintering shrinkage Combination II: 316L(I)/ Fe2Ni(O) Over-PIM can be used to produce parts with dissimilar materials: Magnetic/Non-magnetic Tough/Hard Porous/Dense 10

11 Sintering Behavior Modification Combination I: Fe2Ni(I)/316L(O) Modified sintering shrinkage Combination III: Fe2Ni_1(I)/316L(O) Atom diffusion Good bonding formed due to atom diffusion during the sintering stage. Hardness variation across the boundary 11

12 Porous and Dense Ceramic Part Part design Sintering shrinkage of different ceramic materials Over-injection molding Ceramic part with porous core and dense surface produced by over-pim. Microstructure across boundary Sintered part Green part 12

13 Internal Features Concept Challenges Design σ ts = f ( E, α, L, T, T ) Materials Process Sacrificial material selection and design Binder system Processing parameters 13

14 Ceramic with Internal Channel Concept verification and sacrificial material development Winding internal channels A proprietary sacrificial material developed to form internal features. Complex internal channels were formed in the sintered ceramic part. 14

15 Metallic Closed Impeller Pump impeller Sand casting: Rough surface Labor intensive Limited material selection Closed impeller by over-pim Process development and optimization to produce component with complex internal channels. 15

16 Micro-PIM Motivation: to develop a cost effective manufacturing technique for mass production of micro-component and micro-features. Powder Binder Mixing Injection molding Debinding Sintering Microcomponent Initial powder Feedstock characteristics 200 µm Binder: binder formulations developed for µmim 316L stainless steel Micro features: high aspect ratio microstructure arrays have been fabricated by µmim 500 µm Micro features and micro parts Micro part characteristics 16

17 PIM for Advanced Materials PIM of Titanium Motivation: to reduce the titanium processing cost by net or near net shaping technology Translucent Alumina Motivation: to produce highly dense alumina part by exploring the material and processing 1mm Density: relative density of Ti-6Al-4V has achieved more than 98%. Microstructure: typical laminar structure Mechanical properties: PIM Ti-6Al-4V has achieved comparable to ASTM grade 5. Density: relative density of sintered alumina has achieved 99.5%. Optical properties: transmittance of the sintered alumina for visible light up to 90%. 17

18 Summary PIM is a process combining powder metallurgy and plastic injection molding for mass production of complex metal and ceramic products. Over-PIM was developed to produce multi-functional component with dissimilar materials. Over-PIM was developed to produce complex internal channels with better performance. SIMTech would like to collaborate with industries and research institutes to further enhance PIM capabilities. 18

19 Thank you 19