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1

Comparative Study of the Penetration Characteristics of Ni-Al and Pure Cu Shaped Charge Liners

Liu Yingbin, Zhang Chaoxia, Hu Xiaoyan, Yang Li, Sun Miao, Zhang Zeng, Yuan Lei

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 2

199--222

EN

In order to investigate the correlation between the reactivity of Ni-Al and micro-structural differences in the crater walls, penetration experiments were performed with Ni-Al and pure Cu shaped charge liners (SCLs). The experimental results showed that the average penetration depth of Cu jets is 2.3 times that of Ni-Al jets, but the crater entrance diameter of Ni-Al jets is larger by 26.6%. The microstructure of the recovered targets was characterized using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and a Vickers micro-hardness system. The Ni-Al “white” band was thicker than that of Cu because it releases a lot of heat. The micro-hardness test showed that the “white” band had a relatively high hardness, and the “white” band hardness in the tail was more significant than that in the head. However, the micro-structural evolution of the crater walls is related to the reactivity of Ni-Al, but is also related to other factors. Combined with the macro penetration results and the evolution of the micro-structure of the crater walls, the “white” band can absorb impact energy more strongly and weaken the jet breaking ability or armour protection ability.These results can provide more valuable reference for designing shaped charge warheads and protection structures.

2

Effect of finishing on the corrosion properties of flame sprayed Ni-5%Al and Ni-5%Al-Al2O3 coatings

Charchalis A., Starosta R.

Journal of KONES

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2014

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Vol. 21, No. 4

29--36

EN

The Ni-5%Al alloy and Ni-5% Al-Al2O3 composite coatings were obtained by a flame spraying method, “Casto- Dyn DS 8000” torch was used. The coatings onto a substrate made of austenitic stainless steel (X5CrNi18-10) were sprayed. The coatings were subjected to turning, burnishing and grinding. The evaluation of corrosion properties were based on the measurements of direct current (potentiodynamic method) and the alternating current (EIS method). Corrosion tests were performed in a 3.5% sodium chloride solution. On the basis of studies, the effect of finishing type on the corrosion properties of flame sprayed coatings has been demonstrated. The lowest corrosion current density was found for Ni-5%Al coatings after burnishing, icorr value equal to 0.76 μA/cm2, and the charge transfer resistance was 31063 Ω/cm2. The lowest resistance to corrosion of grinded Ni-5%Al-Al2O3 composite coatings was observed. These coatings were characterized by the following parameters of corrosion process: icorr = 14.01 μA/cm2, Rct = 3260 Ω/cm2. Burnishing caused increased corrosion resistance of both coatings. Due to reduced roughness and waviness are obtained reduction of the area of the actual burnished coatings compared to turned coatings. Thus, it is resulting in reduced values of corrosion current density. After finishing treatment, the thermally sprayed Ni-5%Al-15%Al2O3 coatings characterized by lower corrosion resistance compared to the alloy coating. The presence of the reinforcing phase in the coating promotes the increase of the porosity. Burnishing does not cause a significant change in porosity of the coating. The flame sprayed coatings on nickel-based have a tendency to localized corrosion in seawater environment.

3

Effect of burnishing on the corrosion properties of Ni-5%Al AND Ni-5%Al-15%Al2O3 coatings obtained by plasma spraying

Starosta R.

Journal of KONES

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2014

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Vol. 21, No. 1

273--280

EN

The Ni-5%Al alloy coatings and Ni-5% Al-15%Al2O3 composite coatings were obtained by plasma spraying method. The PN120 gun was used. The coatings onto a shaft made of austenitic stainless steel (X5CrNi 18-10) were sprayed. The coatings were subjected to turning, burnishing. The evaluation of corrosion properties were based on the measurements of corrosion current density and corrosion potential (polarization method), the charge transfer resistance and exponent of constant phase element impedance (electrochemical impedance spectroscopy method). Corrosion tests were performed in replacement seawater (3.5% sodium chloride solution). On the basis of studies, the effect of finishing type on the corrosion properties of plasma sprayed coatings has been demonstrated. The lowest corrosion current density was found for Ni-5% Al coatings after burnishing, icorr value equal to 0.96 A/cm2, and the charge transfer resistance was 27007 Ωcm2. The lowest resistance to corrosion of turned Ni-5%Al-15%Al2O3 composite coatings was observed. These coatings were characterized by the following parameters of corrosion process: icorr = 17.64 A/cm2, Rct = 2137 Ωcm2. Burnishing caused increased corrosion resistance of coatings. Due to reduced roughness and waviness are obtained reduction of the area of the actual burnished coatings compared to turned coatings. Thus, it is resulting in reduced values of corrosion current density. After finishing treatment, the plasma sprayed Ni-5%Al-15%Al2O3 coatings characterized by lower corrosion resistance compared to the alloy coating. The presence of the reinforcing phase in the coating promotes the increase of the porosity. The plasma sprayed coatings on nickel matrix had a tendency to localized corrosion in sodium chloride solution.

4

Analiza procesu kucia matrycowego materiałów wieloskładnikowych otrzymanych z proszku niklu i aluminium

Szczepaniec S., Fludzińska K., Barton G.

Rudy i Metale Nieżelazne

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2008

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R. 53, nr 1

30-37

PL

Przestawiono analizę możliwości kucia matrycowego wyprasek z metalowych materiałów z udziałem faz międzymetalicznych Ni-Al otrzymanych z mieszanki proszków. Badania objęły wpływ konstrukcji narzędzi na płynięcie materiału, które zrealizowano na materiałach modelowych oraz na próbkach wykonanych z mieszanki proszków Ni 78 % mas.- Al 22 % mas. Do symulacji procesu kucia dwuskładnikowych materiałów zaadaptowano procedurę obliczeniową w programie Larstran Shape.

EN

The paper shows the analysis of closed-die forging of PM preforms obtained from a mixture of nickel and aluminium powder. The research of punch construction on material flow was carried out on modelling materials and on the PM preforms from Ni 7 8 % wt.-Al 22 % wt. mixture. The results of a simulation of forming processes of two-component preforms with the Lastran Shape program are presented.