Influence of silicon on growth mechanism of micro-arc oxidation coating on cast Al–Si alloy

Yu, Huijun; Dong, Qing; Yang, Cheng‐Fu; Chen, Chuanzhong

doi:10.1098/rsos.172428

Cited by 19 publications

(7 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ultrahigh temperature on the local surface of the workpiece promotes violent oxidation of both the β-Si and α-Al phase, and leads to a ceramic layer in-situ growing on the surface of Al-Si alloys. Besides, as a simple and eco-friendly technique, the MAO can fabricate coatings with high performance, e.g., high hardness, good anticorrosion and wear resistance [10,11]. In this regard, the MAO technique is more suitable for the surface strengthening of Al-Si alloys [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Tuning the Surface Characteristic of Al-Si Alloys and Its Impacts on the Formation of Micro Arc Oxidation Layers

et al. 2021

Coatings

View full text Add to dashboard Cite

Aluminum Silicon (Al-Si) alloys are the most important among cast alloys and have widespread application. The β-Si phase is detrimental to the growth of micro arc oxidation (MAO) layers on Al-Si alloys. In this paper, the β-Si in the skin layer of different Al-Si alloys was removed by an acid etching pretreatment. Then, the impacts of different etching condition on their MAO process were investigated. Results show that, as etching time was prolonged, the Si content on the surface of Al-12 Si was decreased greatly (less than 0.5 wt.%), and the average size of pores left on the sample surface was increased gradually. This then led to the occurrence of some bigger and more drastic discharge sparks at the earlier oxidation stage. The corresponding layers had a higher ratio of Al2O3 and better corrosion resistance after 30 min of oxidation. Moreover, a 60 s etching pretreatment benefitted and boosted the growth rate and energy efficiency of layers on the Al-9 Si, Al-12 Si and Al-15 Si alloys. Such pretreatment was believed to be applicable to restrain the negative effects of Si on the MAO of different Al-Si alloys.

show abstract

Section: Introductionmentioning

confidence: 99%

Tuning the Surface Characteristic of Al-Si Alloys and Its Impacts on the Formation of Micro Arc Oxidation Layers

et al. 2021

Coatings

View full text Add to dashboard Cite

show abstract

“…In 2018, Yu et al treated a eutectic cast Al-Si alloy using a phosphate-based electrolyte [27]. The PEO processes were performed at a low current density, between 4 and 6 A•dm −2 , and resulted in low-thickness PEO coatings (8-10 µm), in which no α-Al 2 O 3 phase was detected.…”

Section: Peo Coatings Developed On Cast Al-si Alloys Using Phosphate-...mentioning

confidence: 99%

“…Furthermore, Wang & Nie suggested that during passivation, the film grows inward, whereas when Al or Si oxides are formed, there would be some expansion in the volume of the formed layer. According to Yu et al [27], the thickness of the layer created during the initial passivation stage (in the order of nanometers) is significantly lower than the roughness of the substrate (in the order of microns). Thus, these authors believed that the boundary effect prevented the initiation of discharges and proposed a new growth mechanism consisting of three steps: passivation, stable oxidation, and final oxidation stages.…”

Section: Peo Coatings Developed On Cast Al-si Alloys Using Phosphate-...mentioning

confidence: 99%

“…Challenges associated with the treatment of these alloys arise from silicon phases Despite the promising features offered by cast Al-Si alloys, their industrial implementation faces significant limitations, especially in applications that require prolonged durability under aggressive environments. Their poor tribological features, including low wear and abrasion resistances [4,16,27], low hardness, and high tendency to adhesion [28,29], constitute the primary drawbacks. Concerning corrosion resistance, although Al alloys generally provide acceptable corrosion resistance due to their natural oxide layer, this protection is often inadequate under harsh environments, particularly for cast Al-Si alloys, due to the relevant heterogeneities in their chemical composition.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Plasma Electrolytic Oxidation (PEO) as a Promising Technology for the Development of High-Performance Coatings on Cast Al-Si Alloys: A Review

Fernández-López,

Alves,

San-Jose

et al. 2024

Coatings

View full text Add to dashboard Cite

Cast Al-Si alloys, recognized for their excellent mechanical properties, constitute one of the most widely employed non-ferrous substrates in several sectors, and are particularly relevant in the transport industry. Nevertheless, these alloys also display inherent limitations that significantly restrict their use in several applications. Among these limitations, their low hardness, low wear resistance, or limited anti-corrosion properties, which are often not enough when the component is subjected to more severe environments, are particularly relevant. In this context, surface modification and the development of coatings are essential for the application of cast Al-Si alloys. This review focuses on the development of coatings to overcome the complexities associated with improving the performance of cast Al-Si alloys. Against this background, plasma electrolytic oxidation (PEO), an advanced electrochemical treatment that has revolutionized the surface modification of several metallic alloys in recent years, emerges as a promising approach. Despite the growing recognition of PEO technology, the achievement of high-performance coatings on cast Al-Si is still a challenge nowadays, for which reason this review aims to provide an overview of the PEO treatment applied to these alloys. In particular, the impact of the electrolyte chemical composition on the properties of the coatings obtained on different alloys exposed to harsh environments has been analyzed and discussed. By addressing the existing gaps and challenges, this paper contributes to a better understanding of the intricacies associated with the development of robust PEO coatings on cast Al-Si alloys.

show abstract

“…SEM observation of the MAO coating surface shows a characteristic pancake structure whose morphology evolves with the processing conditions [83,[86][87][88]. The cross-sections of the coatings reveal a structure for the thin layers for which there is little distinction between the brittle layer and the dense layer [84,86,89].…”

Section: Composition Of Coatingsmentioning

confidence: 99%

Micro-Arcs Oxidation Layer Formation on Aluminium and Coatings Tribological Properties—A Review

et al. 2023

View full text Add to dashboard Cite

This review proposes to carry out a state-of-the-art associated with micro-arc oxidation. Firstly, the different aspects of the growth mechanisms of the oxides are detailed. Then, the formation of micro-arcs and the case of soft-spark treatment are discussed. Then, the electrolytic reactions involved in the layer construction are outlined. We focused on the influence of aluminium alloys on the appearance of the coating and its characteristics before considering the electrolyte formulation. We have concentrated some of our efforts on silicate-based electrolytes, mainly used in research and industry. The importance of electrical parameters in layer formation is detailed later. The main factors studied in the literature are the current source, current density, treatment frequency and duration, and duty cycle. We have also noted the different phase compositions identified in the literature. Finally, since the process is particularly advantageous for protecting the surfaces of aluminium parts against wear, we conclude this review by presenting work on the tribological properties of this coating. In this final section, we highlight the work on the wear-reducing properties and tribological mechanisms identified in the literature. Particular attention is paid to the relationship between the nature of the substrates used, the role of the electrolyte and the counterpart choice on the friction and wear results.

show abstract

Influence of silicon on growth mechanism of micro-arc oxidation coating on cast Al–Si alloy

Cited by 19 publications

References 45 publications

Tuning the Surface Characteristic of Al-Si Alloys and Its Impacts on the Formation of Micro Arc Oxidation Layers

Tuning the Surface Characteristic of Al-Si Alloys and Its Impacts on the Formation of Micro Arc Oxidation Layers

Plasma Electrolytic Oxidation (PEO) as a Promising Technology for the Development of High-Performance Coatings on Cast Al-Si Alloys: A Review

Micro-Arcs Oxidation Layer Formation on Aluminium and Coatings Tribological Properties—A Review

Contact Info

Product

Resources

About