论文标题
铝合金原子探针标本的纤维预先准备的新方法
New approach for FIB-preparation of atom probe specimens for aluminum alloys
论文作者
论文摘要
来自铝合金的特定地点原子探针断层扫描（APT）受样品制备问题的限制。确实，GA通常用于聚焦离子束（FIB）制剂中，对Al晶界具有很高的亲和力，并引起其封闭。这会导致样品制备后晶界处的高浓度GA，不可靠的组成分析和低样本产量。在这里，为了解决这个问题，我们建议将Cryo-FIB用于APT标本，专门从商业差异中的晶界制备。我们证明了该设置如何易于在常规GA-FIB仪器上实施，可以有效地防止GA扩散到晶界。比较在室温下和低温温度下（低于90k）的样品，我们确认在室温下，在晶界发现了高于15％的Ga的成分富集，而对于较冷冻的样品，则无法检测到未富集。我们建议这是由于低温下GA的扩散速率的降低。目前的结果可能会对铝和合金的理解产生很大的影响。
Site-specific atom probe tomography (APT) from aluminum alloys has been limited by sample preparation issues. Indeed, Ga, which is conventionally used in focused-ion beam (FIB) preparations, has a high affinity for Al grain boundaries and causes their embrittlement. This leads to high concentrations of Ga at grain boundaries after specimen preparation, unreliable compositional analyses and low specimen yield. Here, to tackle this problem, we propose to use cryo-FIB for APT specimen preparation specifically from grain boundaries in a commercial Al-alloy. We demonstrate how this setup, easily implementable on conventional Ga-FIB instruments, is efficient to prevent Ga diffusion to grain boundaries. Specimens were prepared at room temperature and at cryogenic temperature (below approx. 90K) are compared, and we confirm that at room temperature, a compositional enrichment above 15 at.% of Ga is found at the grain boundary, whereas no enrichment could be detected for the cryo-prepared sample. We propose that this is due to the decrease of the diffusion rate of Ga at low temperature. The present results could have a high impact on the understanding of aluminum and Al-alloys.
