Optimization of Cold Spray Process Inputs to Minimize Porosity and Maximize Hardness of Metal Matrix Composite Coatings on AZ31B Magnesium Alloy

The effect of operating gas temperature and powder type on microstructure and mechanical characteristics of cold spraying coatings deposited on EZ33A-T5 magnesium alloy was studied. Three aluminum-based cold spraying powder mixtures Al + Zn, Al + Al2O3 and Al + Zn + Al2O3 were used for the investigation. Deposition was performed using D423 low-pressure cold spray system at operating gas pressure of 1.0 MPa and different temperatures – 300 °C, 450 °C, and 600 °C. The coatings microstructure was investigated with optical and scanning electron microscopy. Mechanical properties of the coatings were characterized through standard test methods for adhesion and cohesion strength, and standard test methods for Vickers hardness of thermal spray coatings. The results demonstrate that with increasing initial gas temperature at spraying nozzle inlet from 300 °C to 600 °C, an increase in the porosity of the coatings of all investigated powder mixtures can be observed. Microstructure characterization showed an increase in porosity from 2.3 % to 4.1 % for Al + Zn powder mixture, from 2.1 % to 3.5 % for Al + Al Al2O3 powder mixture, and from 2.5 % to 5.6 % for Al + Zn + Al2O3 powder mixture. The minimum porosity was obtained at 450 °C for all investigated powder mixtures. Adhesion and cohesion strength and microhardness of coatings were reach their maximum value at 450 °C. The best performance was obtained for Al + Al2O3 powder mixture: coating adhesion – 31.9 MPa (was limited by the bonding strength of the glue), cohesion – 93.5 MPa, microhardness – 81 HV0.15. The influence of Al2O3 particles in the powder mixture on the above-mentioned parameters was also established. The results show that the presence of ceramic particles in powder mixtures can positively affect porosity level and mechanical characteristics.

Section: Introductionmentioning

confidence: 97%

The effect of process temperature and powder composition on microstructure and mechanical characteristics of low-pressure cold spraying aluminum-based coatings

Shorinov

Dolmatov

Polyvianyi

2023

“…These products are the first of their kind, developed in a variety of forms using natural fibers. Krishnudu et al [23] examined the optimization of the reinforcement ratios, and the optimum values of reinforcement are recommended in order to increase the mechanical characteristics [24][25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Investigation on Mechanical characterization of abutilon indicum fiber nonwoven fabric reinforced epoxy composite materials

Mohanraj¹,

Rameshkumar²,

Mathanbabu³

et al. 2023

Self Cite

Natural fibres find their way into many engineering applications in the automobile and aerospace sectors owing to their eco-friendly nature. Natural fiber produced from agricultural residue, is capable of enhancing the mechanical and thermal properties of composite materials while lowering their overall cost. The main aim of the current study is to investigate such natural fiber, nonwoven fabric reinforced composites. In this work, samples reinforced by non-woven Abutilon indicum (AI) fibre are manufactured with varying fibre weight percentages, such as 20 %, 25 %, 30 %, 35 %, 40%, using the hand layup method and needle-punching process to make the fabric and composite. Mechanical tests such as tensile, flexural, and compressive tests were using a universal testing machine, and impact tests were performed using an izod impact tester, in addition to morphological and thermal studies were performed on the above composites and their respect compositions. The effect of the fibres on FTIR and TGA was also investigated. In order to understand the bonding behaviors and the fractured composite specimens were examined by a scanning electron microscope (SEM). The findings revealed that the highest values of tensile and flexural strength were observed to be 39.796 MPa and 62.329 MPa at 35 wt. % fibre and maximum impact strength and compressive strength were 0.441 joules and 47.45 Mpa at 35 wt. % fibre.

“…Hence, it can be concluded that the results of single-factor experiments obtained in the study of multi-factor systems are often of little use for practical application. For the investigation of multi-factor systems, it is most appropriate to use statistical methods of experiment design, which make it possible to obtain models of multi-factor processes with a minimum number of runs [40][41][42][43][44].…”

Section: Introductionmentioning

confidence: 99%

Optimization of cold spray process parameters to maximize adhesion and deposition efficiency of Ni+Al₂O₃ coatings

Shorinov,

Dolmatov,

Polyviany

et al. 2023

The paper considers the conducted study of the complex effect of low-pressure cold spraying parameters, namely the nozzle inlet temperature, stand-off distance, and powder feed rate on the adhesion and deposition efficiency of coatings from a Ni+Al2O3 powder on VT3-1 titanium alloy substrate. Based on predetermined information, the main levels and intervals of factor variation were selected. The dependence of the adhesion and deposition efficiency on the selected variables was approximated by a second-order polynomial. In accordance with the developed matrix of the experiment (central compositional design), a coating of the studied powder was deposited. The average value of these parameters was determined using standard methods for studying the adhesion strength (ASTM C603) and the deposition efficiency for thermal spray coatings. Based on the results of experimental data, regression equations were obtained for adhesion and deposition efficiency. For the purpose of checking the adequacy of the model, an analysis of variance was performed. It was confirmed that the obtained empirical dependences can be used to predict the adhesion and deposition efficiency of cold spraying of coatings from a Ni+Al2O3 powder on VT3-1 titanium alloy in the specified ranges of values of spraying parameters. Multi-factor optimization of the spraying parameters in order to obtain maximum values of adhesion strength and deposition efficiency was performed using the response surface methodology in the Stat-Ease 360 software. Three-dimensional and contour graphs of the dependence of the adhesion and deposition efficiency on the studied parameters were developed from the obtained empirical models. The optimal combination of parameters of low-pressure cold spraying, which ensures the maximum adhesion (34.78 MPa) and deposition efficiency (29.46%) of the Ni+Al2O3 coating mixture, is the nozzle inlet temperature—537 °C, stand-off distance—11 mm, and powder feed rate—0.6 g s−1.