*Article* **Improvements of Arboblend V2 Nature Characteristics through Depositing Thin Ceramic Layers**

**Simona-Nicoleta Mazurchevici <sup>1</sup> , Alina Marguta <sup>1</sup> , Bogdan Istrate <sup>2</sup> , Marcelin Benchea <sup>2</sup> , Mihai Boca <sup>1</sup> and Dumitru Nedelcu 1,3,\***


**Abstract:** The paper aims to investigate the behavior of Arboblend V2 Nature biopolymer samples covered with three ceramic powders, Amdry 6420 (Cr2O<sup>3</sup> ), Metco 143 (ZrO<sup>2</sup> 18TiO<sup>2</sup> 10Y2O<sup>3</sup> ) and Metco 136F (Cr2O<sup>3</sup> -xSiO<sup>2</sup> -yTiO<sup>2</sup> ). The coated samples were obtained by injection molding, and the micropowder deposition was achieved by using the Atmospheric Plasma Spray (APS) method, with varied thickness layers. The present study will only describe the results for nine-layer deposition because, as the number of layers' increases, the surface quality and mechanical/thermal characteristics such as wear, hardness and thermal resistance are also increased. The followed determinations were conducted: the adhesion strength, hardness on a microscopic scale by micro-indentation, thermal analysis and structural and morphological analysis. The structural analysis has highlighted a uniform deposition for the ZrO<sup>2</sup> 18TiO<sup>2</sup> 10Y2O<sup>3</sup> layer, but for the layers that contained Cr2O<sup>3</sup> ceramic microparticles, the deposition was not completely uniform. The thermal analysis revealed structural stability up to a temperature of 230 ◦C, the major degradation of the biopolymer matrix taking place at a temperature around 344 ◦C. The samples' crystalline structure as well as the presence of the Cr2O<sup>3</sup> compound significantly influenced the micro-indentation and scratch analysis responses. The novelty of this study is given by itself the coating of the Arboblend V2 Nature biopolymer (as base material), with ceramic microparticles as the micropowder coating material. Following the undertaken study, the increase in the mechanical, tribological and thermal characteristics of the samples recommend all three coated biopolymer samples as suitable for operating in harsh conditions, such as the automotive industry, in order to replace plastic materials.

**Keywords:** biodegradable thermoplastic; coating; Amdry 6420; Metco 143; Metco 136F; hardness; adhesion; structure
