Microstructural Parameters and Their Effect on the Indentation Hardness of Electrodeposited and Annealed Nickel-Iron Micro-Specimens

• Published in: Advanced engineering materials 2013-06, Vol.15 (6), p.442-448
• Main Authors: Schmitt, Martin-T., Hoffmann, Joachim E., Eifler, Dietmar
• Format: Article
• Language: English
• Subjects: Annealing; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Grain size; Indentation; Lattice strain; Mechanical and acoustical properties of condensed matter; Mechanical properties of nanoscale materials; Microstructure; Nanocrystals; Physics; Surface layer; Texture
• ISSN: 1438-1656; 1527-2648
• DOI: 10.1002/adem.201200253

Using the direct‐LIGA technology, nickel–iron micro‐specimens are serially produced by a micro‐gear drive manufacturer and subsequently annealed within the temperature range between 180 and 800 °C. The microstructure (grain size, lattice strain, and texture) is characterized using XRD measurements. Following electrodeposition, nano‐crystalline microstructures result with grain size of approximately 10 nm. The transmission electron microscope images confirm the XRD results. The lattice strain decreases in the temperature range from 200 to 300 °C and grain growth results for an annealing temperature from approximately 260 °C. The annealing treatment produced no essential changes in the material's texture. Analysis of the indentation hardness and indentation modulus demonstrates considerable changes above 200 °C. Using the direct‐LIGA technology, nickel–iron micro‐specimens are serially produced by a micro‐gear drive manufacturer and subsequently annealed within the temperature range between 180 and 800 °C. The microstructure (grain size, lattice strain, and texture) is characterized using XRD measurements. Following electrodeposition, nano‐crystalline microstructures result with grain size of approximately 10 nm. The transmission electron microscope images confirm the XRD results. The lattice strain decreases in the temperature range from 200 to 300 °C and grain growth results for an annealing temperature from approximately 260 °C. The annealing treatment produced no essential changes in the material's texture. Analysis of the indentation hardness and indentation modulus demonstrates considerable changes above 200 °C.