Laser-induced plasmas and reactions therein depend on the ablated target's chemical composition and morphology. Recently, we have characterized plasma properties such as spatiotemporal morphology, electron density, species temperature within the plasma, ionization degree, etc. for pure Al under variations in morphology. Here, we utilize a bi-metal powder system to study similar characteristics as a function of powder chemistry. Micron-sized ball milled Al/Zr composites of three chemistries (3Al:2Zr, Al:Zr, and Al:3Zr) are compared to similarly-sized pure Al, pure Zr, and a mixture of Al + Zr powder. We find that the introduction of increasing concentrations of Zr has several interesting effects on the plasma compared to pure Al, including a dramatic increase in the electron density (to ~1–5 × 10¹⁷ cm⁻³), and the earlier onset of ZrO emission bands which have a higher disassociation energy and are thermodynamically preferred over AlO at high temperatures. Differences in plume morphology, the spatial distribution of molecular species, and the emission intensities of ZrO, Zr I and Al I were observed for Al + Zr and ball-milled Al:Zr samples, indicating the influence of microstructure on the chemical reactions. We measured plasma temperatures using the Saha-Boltzmann plot method; the composites demonstrate higher temperatures than pure Zr, Al + Zr mixtures, and pure Al. We observe only minor differences in temperature as a function of increasing Zr-content within the composites. This work continues to build on our understanding of the relationships between plasma properties and microsecond-timescale chemical reactions of reactive materials.

激光诱导等离子体和其中的反应取决于烧蚀目标的化学成分和形态。最近，我们已经表征了纯铝在形态变化下的等离子体特性，例如时空形态、电子密度、等离子体内的物种温度、电离度等。在这里，我们利用双金属粉末系统来研究作为粉末化学函数的类似特征。三种化学成分（3Al:2Zr、Al:Zr 和 Al:3Zr）的微米级球磨 Al/Zr 复合材料与类似尺寸的纯 Al、纯 Zr 和 Al + Zr 粉末的混合物进行了比较。我们发现，与纯铝相比，引入浓度增加的 Zr 对等离子体有几个有趣的影响，包括电子密度的显着增加（至 ~1–5 × 10 ¹⁷  cm⁻³)，以及较早出现的 ZrO 发射带，其具有更高的解离能，并且在高温下在热力学上优于 Al2O3。观察到 Al + Zr 和球磨 Al:Zr 样品的羽流形态、分子种类的空间分布以及 ZrO、Zr I 和 Al I 的发射强度的差异，表明微观结构对化学反应的影响。我们使用 Saha-Boltzmann 绘图方法测量了等离子体温度；复合材料表现出比纯 Zr、Al + Zr 混合物和纯 Al 更高的温度。我们仅观察到温度随复合材料中 Zr 含量增加而产生的微小差异。这项工作继续建立在我们对等离子体特性与反应材料的微秒级化学反应之间关系的理解的基础上。