Jakob Severin, Thuvander Mattias
Department of Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
Microsc Microanal. 2025 Feb 3;30(6):1163-1171. doi: 10.1093/mam/ozae069.
The accuracy of carbon composition measurement of carbide precipitates in steel or other alloys is limited by the evaporation characteristics of carbon and the performance of current detector systems. Carbon evaporates in a higher fraction as clustered ions leading to detector pile-up during so-called multiple hits. To achieve higher accuracy, a grid was positioned behind the local electrode, reducing the detection efficiency from 52 to 7% and thereby reducing the fraction of multi-hit events. This work confirms the preferential loss of carbon due to detector pile-up. Furthermore, we demonstrate that the newer generation of commercial atom probe instruments displays somewhat higher discrepancy of carbon composition than previous generations. The reason for this might be different laser-matter interaction leading to less metal ions in multi-hit events.
钢或其他合金中碳化物析出物碳成分测量的准确性受到碳的蒸发特性和当前检测系统性能的限制。碳以更高比例以簇状离子形式蒸发，导致在所谓的多次撞击期间探测器堆积。为了实现更高的准确性，在局部电极后面放置了一个栅格，将检测效率从52%降低到7%，从而减少了多次撞击事件的比例。这项工作证实了由于探测器堆积导致碳的优先损失。此外，我们证明新一代商业原子探针仪器显示出的碳成分差异比前几代仪器略高。其原因可能是不同的激光与物质相互作用导致多次撞击事件中的金属离子减少。
