کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
675094 | 1459590 | 2009 | 6 صفحه PDF | دانلود رایگان |
The purpose of this report is to present a methodology to record continuous cooling precipitation (CCP) diagrams over the complete range of technical interesting cooling rates for some aluminium wrought alloys. With the information out of CCP-diagrams, the quenching step of the heat-treatment process “Age Hardening” can be optimized. The nanosized precipitations were detected via Differential Scanning Calorimetry (DSC) by identifying their exothermal heat. Aluminium wrought alloy EN AW-6005A was age hardened in three different DSCs whereby cooling rate range varies over 3 orders of magnitude. With increasing cooling rate, the precipitation heat is decreasing. The CCP-diagram covers cooling rates form close to equilibrium conditions at 0.1 K/min up to the critical cooling rate at 375 K/min where the precipitation reaction is suppressed completely. The DSC delivers a very useful method to record full range CCP-diagrams of aluminium alloys. Opposite to other possible methods, it also delivers a measure for the amount of the nanosized precipitates by the amount of released heat. A strategy is presented for the deconvolution of overlapping DSC-peaks.
Journal: Thermochimica Acta - Volume 492, Issues 1–2, 10 August 2009, Pages 73–78