scholarly journals Study on Preparation of Aluminum Ash Coating Based on Plasma Spray

2019 ◽  
Vol 9 (23) ◽  
pp. 4980 ◽  
Author(s):  
Lv ◽  
Zhang ◽  
Ni ◽  
Wang ◽  
Zhu ◽  
...  
Keyword(s):  
Plasma Spray ◽  
Orthogonal Experiment ◽  
Raw Material ◽  
Atmospheric Plasma ◽  
Angle Of Repose ◽  
Powder Flow ◽  
Comprehensive Performance ◽  
Abrasion Rate ◽  
Powder Flow Rate ◽  
Water Hydrolysis

Ultimate aluminum ash (UAA) was used as the key raw material to prepare ultimate spray powder (USP) via water hydrolysis and ball milling, after which the coating was prepared by atmospheric plasma spray. The flowability of the USP was evaluated by the angle of repose; the process parameters of the coating were determined by orthogonal experiment, and the microstructure and properties of the coating were characterized. The results show that the ultimate spray powder after granulation has an angle of repose less than 40°, which meets the requirements of plasma spray. When the spray current is 600 A, the spray voltage is 55 V, the powder flow rate is 22 g/min, and the main air flow is 33 lspm, the prepared ultimate coating has the best comprehensive performance. The microhardness of the coating is 512 HV, which is about 1.5 times the hardness of the substrate; the abrasion rate is 18.53 × 10–3 g/min; the porosity is 0.17% and the average adhesive strength is 8.78 Mpa, which confirms the feasibility of using aluminum ash as a spray powder to prepare a coating.

scholarly journals Preparation and Performance Optimization of Original Aluminum Ash Coating Based on Plasma Spraying

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 770 ◽  
Author(s):  
Hongjun Ni ◽  
Jiaqiao Zhang ◽  
Shuaishuai Lv ◽  
Xingxing Wang ◽  
Yu Zhu ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Plasma Spray ◽  
Performance Optimization ◽  
Gas Flow ◽  
Orthogonal Experiment ◽  
Angle Of Repose ◽  
Spray Parameters ◽  
Coating Properties ◽  
Industrial Solid Waste ◽  
And Performance

As an industrial solid waste, the original aluminum ash (OAA) will cause serious pollution to the air and soil. How to reuse the OAA has been a research difficulty. Thus, a method of preparing a plasma spray powder using OAA is proposed. The OAA was hydrolyzed and ball milled, and the flowability of original aluminum ash spray powder (OAASP) was evaluated by the angle of repose. The coating properties were determined via analyzing the microstructure and the phase of the coating, and the effects of plasma spray parameters on the coating properties were investigated by the orthogonal experiment to optimize spray parameters. The results show that the angle of repose of OAASP after granulation was less than 40°, which met the requirements of plasma spraying. When the spraying current was 600 A, the spraying voltage was 60 V, the main gas flow was 33 slpm, and the powder flow rate was 22 g/min, and the prepared original aluminum ash coating (OAAC) had excellent comprehensive performance. After the spraying process parameters were optimized, the microhardness of the coating was 606.54 HV, which is about twice the hardness of the substrate; the abrasion rate was 12.86 × 10−3 g/min; the porosity was 0.16%; and the adhesive strength was 16 MPa. When the amount of Al2O3 added was 50%, the hardness of the coating was increased by 17.61%.

Optimization of Alumina Slurry Properties and Drying Conditions in the Spray Drying Process and Characterization of Corresponding Coating Fabricated by Atmospheric Plasma Spray

2011 ◽  
Vol 484 ◽  
pp. 158-165
Author(s):  
Yu Bai ◽  
Jian Feng Yang ◽  
S.W. Lee
Keyword(s):  
Surface Roughness ◽  
Plasma Spray ◽  
Orthogonal Experiment ◽  
Atmospheric Plasma Spray ◽  
Influential Factor ◽  
Atmospheric Plasma ◽  
Micro Hardness ◽  
Average Grain Size ◽  
Drying Conditions ◽  
Sprayed Coatings

In this paper, alumina (Al2O3) slurry properties and spraying drying conditions were optimized by orthogonal experiment for preparing the dense and spherical alumina feedstock. The feedstock was carried in a moving gas stream and deposited on the stainless substrate by atmospheric plasma spray (APS).The phase composition and microstructure of feedstock and as-sprayed coatings were studied by XRD, SEM and TEM. In addition, the porosity, surface roughness and micro hardness of as-sprayed coatings were also investigated. The results showed that Al2O3 powder content in slurry was the most influential factor for the particle size and morphology of feedstock and most of α-Al2O3 existing in the starting feedstock transformed into γ-Al2O3 during APS. Moreover, it was found that, using the feedstock prepared by optimized parameters, the as-sprayed coating had an average grain size of about 250 nm, with lower porosity of about 4 %, surface roughness Ra of about 1.94 μm, micro hardness HV0.3 of about 1000 under applied load 300 g.

Variable Powder Flow Rate Control in Laser Metal Deposition Processes

2008 ◽  
Author(s):  
Lie Tang ◽  
Jianzhong Ruan ◽  
Robert G. Landers ◽  
Frank Liou
Keyword(s):  
Transport System ◽  
Flow Rate ◽  
Rate Control ◽  
Metal Deposition ◽  
Powder Flow ◽  
Laser Metal Deposition ◽  
Motion System ◽  
Powder Flow Rate ◽  
Deposition Processes ◽  
Flow Rate Control

This paper proposes a novel method, called Variable Powder Flow Rate Control (VPFRC), for the regulation of powder flow rate in laser metal deposition processes. The idea of VPFRC is to adjust the powder flow rate to maintain a uniform powder deposition per unit length even when disturbances occur (e.g., the motion system accelerates and decelerates). Dynamic models of the powder delivery system motor and the powder transport system (i.e., five–meter pipe, powder dispenser, and cladding head) are constructed. A general tracking controller is then designed to track variable powder flow rate references. Since the powder flow rate at the nozzle exit cannot be directly measured, it is estimated using the powder transport system model. The input to this model is the DC motor rotation speed, which is estimated on–line using a Kalman filter. Experiments are conducted to examine the performance of the proposed control methodology. The experimental results demonstrate that the VPFRC method is successful in maintaining a uniform track morphology, even when the motion system accelerates and decelerates.

Fabrication and Ablation Behavior of Plasma Sprayed ZrC-W Composite Coatings

2014 ◽  
Vol 602-603 ◽  
pp. 552-555
Author(s):  
Dan Lu ◽  
Ya Ran Niu ◽  
Xue Lian Ge ◽  
Xue Bing Zheng ◽  
Guang Chen
Keyword(s):  
Thermal Conductivity ◽  
Thermal Shock ◽  
Plasma Spray ◽  
Composite Coatings ◽  
Lamellar Microstructure ◽  
Atmospheric Plasma Spray ◽  
Atmospheric Plasma ◽  
Plasma Flame ◽  
Plasma Sprayed ◽  
Zrc Coating

In this work, atmospheric plasma spray (APS) technology was applied to fabricate ZrC-W composite coatings. The microstructure of the composite coatings was characterized. The influence of W content on the ablation-resistant and thermal shock properties of ZrC-W composite coatings was evaluated using a plasma flame. The results show that the ZrC-W composite coatings had typically lamellar microstructure, which was mainly made up of cubic ZrC, cubic W and a small amount of tetragonal ZrO2. The ZrC-W coatings had improved ablation resistant and thermal shock properties compared with those of the pure ZrC coating. It was supposed that the improved density, thermal conductivity and toughness of the composite coatings contributed to this phenomenon.

Plasma-Spray-Forming of Alumina Matrix Composite Reinforced with Metal Thin Wire

2000 ◽  
Author(s):  
S. Sodeoka ◽  
T. Inoue ◽  
M. Suzuki
Keyword(s):  
Plasma Spray ◽  
Spray Forming ◽  
Filament Winding ◽  
Atmospheric Plasma ◽  
Thin Wire ◽  
Alumina Matrix ◽  
Plasma Spray Forming ◽  
Inconel 600 ◽  
The Matrix ◽  
The Wire

Abstract Alumina matrix composites reinforced with metal thin wire (Inconel-600) were successfully fabricated by plasma spray forming. The atmospheric plasma sprayed matrix layers and wire layers arranged by filament-winding technique were piled up alternately. Though the matrix and the wire were partially bonded only on the side which sprayed particles came flying to, a solid structure was obtained by this technique. Spraying in one direction perpendicular to the substrate made peculiar V-shape pores around the wires, but tilting the torch was effective to reduce the pores. The flexural strength of composite did not increase in spite of some crack deflections on the fracture surface. Owing to the wire pullout, however, the composite exhibited a remarkably higher apparent fracture energy than that of monolithic alumina ceramics.

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