In suspension spraying, two most frequently used solvents are water and ethanol. In this study, we test the potential of using alternative, high molecular weight solvent and demonstrate the associated advantages. For that, two organic solvents are directly compared: ethanol (serving as a benchmark, suspension formulated at 10 wt.% solid load) and di-propylene glycol methyl ether (two suspensions at 10 wt.% and 20 wt.% solid load). As a model material, \(\hbox {Al}_{2}\hbox {O}_3\) is selected, a frequently sprayed ceramics employed in many industrial sectors. Sub-micron 100% alpha-alumina powder is used to formulate the suspensions. Identical spray conditions are then used to deposit the coatings using hybrid water-stabilized plasma torch. Shadowgraphy monitoring of the suspension fragmentation as well as in situ measurement of the particle in-flight properties is employed, showing no significant differences between the three series. Further, it is shown that the ethanol- and ether-based-feedstock coatings are fully comparable in terms of their microstructure, porosity content, surface roughness as well as hardness and adhesion to the substrates. Importantly, the ether-based coatings exhibit slightly higher levels of \(\alpha\)-\(\hbox {Al}_{2}\hbox {O}_3\) phase when compared to their ethanol-based counterpart (17 wt.% vs. 6 wt.%). The use of 20 wt.% solid load in the ether solvent leads to twofold increase in the deposition rate while (as opposed to ethanol) successfully retaining a dense microstructure. Lastly, the ether is significantly cheaper and safer to handle than ethanol.

在悬浮液喷涂中，两种最常用的溶剂是水和乙醇。在这项研究中，我们测试了使用替代的高分子量溶剂的潜力，并证明了相关的优势。为此，直接比较两种有机溶剂：乙醇（作为基准，以10重量％固含量配制的悬浮液）和二丙二醇甲醚（两种分别为10重量％和20重量％固含量的悬浮液） 。作为模型材料，\（\ hbox {Al} _ {2} \ hbox {O} _3 \）选择一种在许多工业领域使用的经常喷涂的陶瓷。使用亚微米的100％α-氧化铝粉末配制悬浮液。然后使用混合水稳定的等离子炬，使用相同的喷涂条件来沉积涂层。进行了悬浮液碎裂的影象监测以及飞行中粒子的原位测量，显示这三个系列之间没有显着差异。此外，显示出基于乙醇和醚的原料涂层在微观结构，孔隙率含量，表面粗糙度以及硬度和对基材的粘附性方面是完全可比的。重要的是，基于醚的涂料表现出较高水平的\（\ alpha \） - \（\ hbox {Al} _ {2} \ hbox {O} _3 \）与基于乙醇的同类产品相比（17 wt。％vs. 6 wt。％）。在醚溶剂中使用20重量％的固体负载导致沉积速率增加两倍，而（与乙醇相反）成功地保持了致密的微观结构。最后，乙醚比乙醇便宜得多，并且处理起来更安全。