TY - CONF A1 - Cobet, C. A1 - Wollschläger, Nicole A1 - Esser, N. A1 - Richter, W. A1 - Baudach, Steffen A1 - Beck, Uwe A1 - Männ, Marion A1 - Brunn, S. A1 - Gruska, B. A1 - Richter, U. T1 - VUV-XUV-Ellipsometrie mit Synchrotronstrahlung T2 - 2. Workshop Ellipsometrie CY - Berlin, Deutschland DA - 2002-02-18 PY - 2002 AN - OPUS4-2282 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wandel, K. A1 - Procop, Mathias A1 - Richter, U. A1 - Wolf, R. T1 - The influence of the storage time and the deposition of SiO2 on the properties of H2SO4 etched (In,Ga) As surface layers investigated by XPS and ellipsometry PY - 1993 SN - 0268-1242 SN - 1361-6641 VL - 8 SP - 1438 EP - 1444 PB - IOP Publ. CY - Bristol AN - OPUS4-7087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, U. A1 - Mischke, R. A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Eigenfeld, K. A1 - Arendholz, S. T1 - Porosity detection in high pressure die castings - Part 1 - Microscopic investigations of pores in HPD castings N2 - Ever larger high pressure die castings (HPDC) with ever thinner walls raise the issue of castings defects. Properties of components are often strongly influenced by inner porosity. In the case of high pressure die castings, shrinkage and gas porosity occur. Two possibilities of characterizing porosity – by microscopy and active thermography – are dealt with in two articles. In this article, the microscopic investigations are presented. In a second article, first the feasibility of thermographic detection will be discussed based on simulations and, thereafter, the experimental determination of porosity with active thermography will be described. KW - Die casting KW - Aluminium KW - Pores KW - Microscopy KW - Active thermography KW - NDT PY - 2015 SN - 0046-5933 IS - 1 SP - Beitrag 03, 1 EP - 10 PB - Gießerei-Verl. CY - Düsseldorf AN - OPUS4-33111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, U. A1 - Mischke, R. A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Eigenfeld, K. T1 - Porosity detection in high pressure die castings - Part 2 - Non-destructive characterization of pores in HPD castings using active thermpography: numerical simulation and experimental validation N2 - Ever larger high pressure die castings (HPDC) with ever thinner walls raise the issue of casting defects. Properties of components are often strongly influenced by inner porosity. In the case of high pressure die castings, shrinkage and gas porosity occur. Two possibilities of characterizing porosity - by microscopy and acitve thermography - are dealt with in two articles. In the previous article, the microscopic investigations are presented. In this article, first the feasibility of thermographic detection will be discussed based on simulations and, thereafter, the experimental determination of porosity with active thermography will be described. KW - Porosity KW - Aluminium KW - HPD casting KW - Active thermography KW - Flash KW - Numerical simulation PY - 2015 SN - 0046-5933 VL - 67 IS - 2 SP - 38 EP - 47 PB - Gießerei-Verl. CY - Düsseldorf AN - OPUS4-34283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Myrach, Philipp A1 - Röllig, Mathias A1 - Jonietz, Florian A1 - Illerhaus, Bernhard A1 - Meinel, Dietmar A1 - Richter, U. A1 - Miksche, R. ED - Chimenti, Dale E. ED - Bond, Leonard J. T1 - Characterization of pores in high pressure die cast aluminum using active thermography and computed tomography N2 - Larger high pressure die castings (HPDC) and decreasing wall thicknesses are raising the issue of casting defects like pores in aluminum structures. Properties of components are often strongly influenced by inner porosity. As these products are being established more and more in lightweight construction (e.g. automotive and other transport areas), non-destructive testing methods, which can be applied fast and on-site, are required for quality assurance. In this contribution, the application of active thermography for the direct detection of larger pores is demonstrated. The analysis of limits and accuracy of the method are completed by numerical simulation and the method is validated using computed tomography. T2 - 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Minneapolis, Minnesota, USA DA - 26.07.2015 KW - flash thermography KW - aluminum KW - pores KW - computed tomography PY - 2016 SN - 978-0-7354-1353-5 DO - https://doi.org/10.1063/1.4940580 VL - 1706 SP - 110009-1 EP - 110009-8 PB - AIP Publishing LLC CY - Melville, New York, USA AN - OPUS4-35848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -