The Mystery of Molten Metal
Recent advances in scientific understanding of high-temperature materials processing using novelexperimental methodologies have shed light on the complex role of surface and interface phenomena. New in-situ studies onmolten metal/solid ceramic interactions using a unique experimental complex at the Foundry Research Institute, Krakow,have revealed a number of unusual observations in materials processing at high temperatures. We present some suchunusual observations and their explanation with reference to liquid metal processing of Al, Ni, and Ti, and their alloys incontact with oxide ceramics. In particular, we focus on the following aspects: primary oxidation of Al from residual watervapor or oxygen, capillary purification to remove surface oxide, substrate protection by CVD carbon, roughening due tospinel whisker formation, inclusions in castings due to mechanical detachment, floatation due to buoyancy forces, andsegregation due to directional solidification, modification of the solid surface morphology by metal vapor ahead of the liquid,and the complications due to multi-component alloys melted in crucibles made from complex oxide-based ceramics. In thecase of Ti, rapid reactions with oxides result in undesirable volumetric changes that create difficulty in casting high-quality Tiparts, particularly by investment casting. Nanoscale (e. g. , colloidal) coatings based on Y2O3 protect crucibles and holdingladles agAlnst such attack. Practical insights and recommendations for materials processing emerging from the fundamentalstudies on high-temperature interfacial phenomena have been described.
molten metal high-temperature phenomena in situ observation casting defects
Natalia Sobczak Jerzy Sobczak Rajiv Asthana Robert Purgert
Foundry Research Institute, 73 Zakopianska Street, 30418 Cracow, Poland Department of Engineering & Technology, University of Wisconsin-Stout, Menomonie, WI 54751, USA Energy Industries of Ohio, Park Center Plaza, Suite 200,6100 Oak Tree Boulevard, Independence, OR 44
国际会议
69th World Foundry Congress(第69届世界铸造会议 WFC 2010)
杭州
英文
19-32
2010-10-16（万方平台首次上网日期，不代表论文的发表时间）