Residual Stresses, Plastic Work, and Microhardness in Cryogenic Machining of Inconel 718
2011 (English)In: 4th International Swedish Production Symposium / [ed] Jan-Eric Stål, Lund: Swedish Production Academy , 2011, 283-288 p.Conference paper (Refereed)
In machining of superalloys, a major quality performance characteristic refers to the integrity of the machined surface. In this consideration, the paper deals with a comparative evaluation of surface integrity in dry, minimum quantity lubrication (MQL), and cryogenic turning of Inconel 718. The comparison is concerned with residual stresses, plastic work, and microhardness developed under these different cooling lubrication conditions. The residual stresses generated on the workpiece surface were more tensile in the tangential (hoop) direction than in the axial direction. On the other hand, larger compressive stresses beneath the surface were observed in the axial direction. We have clearly observed that cryogenic machining resulted in higher compressive residual stresses when compared with dry or MQL machining. In addition, cryogenic machining yielded a thicker compressive zone of material beneath the machined surface. The correlation between residual stresses and plastic work suggested that the effects of mechanical loads, in comparison with thermal effects, were minor. It was further shown that the highest machined surface hardness was related to cryogenic cooling lubrication. In contrast to the microhardness variation, no drastic change in microstructure was observed. Moreover, no significant correlation between thermally induced phase transformation in a machined surface layer and microhardness was established.
Place, publisher, year, edition, pages
Lund: Swedish Production Academy , 2011. 283-288 p.
Machining, Cryogenic, Nickel, Alloy, Surface integrity
Production Engineering, Human Work Science and Ergonomics
Research subject SRA - Production
IdentifiersURN: urn:nbn:se:kth:diva-39539OAI: oai:DiVA.org:kth-39539DiVA: diva2:440077
The 4th International Swedish Production Symposium. Lund, Sweden. 3rd – 5th of May 2011
ProjectsEUREKA E!4550 PRO-FACTORY SUSCRYMAC
FunderXPRES - Initiative for excellence in production research
QC 201111152011-09-122011-09-122012-06-19Bibliographically approved