Combustion of mechanically activated Ni/Al reactive composites with microstructural refinement tailored using two-step milling

Mason, B. Aaron; Sippel, Travis R.; Groven, Lori J.; Gunduz, I. Emre; Son, Steven F.

doi:10.1016/j.intermet.2015.06.009

Cited by 25 publications

(8 citation statements)

References 34 publications

(42 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The DSC scans on Fig. 3 show at least three exothermic peaks, which are associated with the formation of NiAl 3 , Ni 2 Al 3 and NiAl as observed in other studies on ball milled powders and microscale multilayers [17,20,22]. The absence of any endothermic peaks indicate that all the Al reacted to form intermetallic compounds before reaching its melting point.…”

Section: Thermal Analysissupporting

confidence: 69%

“…Nanoscale multilayers of this system produced using magnetron sputtering ignite at the solid state and react at much larger velocities due to reduced diffusion distances and possible formation of metastable states [11][12][13][14]. Similarly, mechanical activation (MA) using ball milling can be used to form particles consisting of Ni-Al laminates with nanoscale dimensions having similar combustion properties [15][16][17][18][19][20][21][22][23]. Due to the rapid nature of the reactions, it has been challenging to identify phase formation sequences in these nanostructured systems.…”

Section: Ni 2 Al 3 Andmentioning

confidence: 99%

See 1 more Smart Citation

Microscopic two-color infrared imaging of Ni Al reactive particles and pellets

2016

Self Cite

View full text Add to dashboard Cite

Non-contact temperature measurements using infrared detection are widely used for observing combustion in reactive materials. The most common method used is multicolor ratio pyrometry, where point measurements are taken at different wavelengths and the ratios are used to estimate temperatures. It is desirable to perform spatially and temporally resolved measurements at high speeds. We report a new design that employs optical elements coupled with a high-speed infrared camera. The system has a spatial resolution of 14 micrometers/pixel and can go as high as 3900 frames per second, while simultaneously obtaining images at two different wavelengths. The system was calibrated with a black body source to permit calculation of emissivities in addition to temperatures. Reactions were observed in single particles of mechanically activated nickel-aluminum and their pellets fabricated by cold pressing. The particles were ignited using a CO 2 laser heated hot plate at 670 K, whereas the pellets were ignited using an electrical spark. The particles show multiple reaction stages corresponding to melting of aluminum and peritectic decomposition of NiAl 3 and Ni 2 Al 3 , with maximum temperatures reaching 1450 K, before thermal losses quench further reactions. Particles within a reacting pellet go through the same stages, but continue reacting due to the additional heating from the neighboring particles and reach

show abstract

Section: Thermal Analysissupporting

confidence: 69%

Section: Ni 2 Al 3 Andmentioning

confidence: 99%

Microscopic two-color infrared imaging of Ni Al reactive particles and pellets

2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…The thermodynamic modification is therefore necessary to improve its usability and reliability. Several reactive Al-Ni systems have been produced by methods like combustion synthesis [8], mixing and pressing of powders [9,10], welding [11,12], forging [13], rolling [14,15], vacuum deposition [11,15], cladding [16], and high energy ball milling [17][18][19]. It is well-known fact that the reactivity of these composites depends strongly on their corresponding microstructures.…”

Section: Introductionmentioning

confidence: 99%

Exothermic Reaction Kinetics in High Energy Density Al-Ni with Nanoscale Multilayers Synthesized by Cryomilling

Han

et al. 2018

Metals

View full text Add to dashboard Cite

Abstract:The Al-Ni system is known as a high energy density materials (HEDM) because of its highly exothermic nature during intermetallic compound (IMC) formation. In this study, elemental Al and Ni powder were milled to explore the effect of cryomilling atmosphere on the microstructure and exothermic behavior. Scanning electron microscope (SEM) observations show continuous structural refinement up to 8 h of cryomilling. No IMC phase was detected in the X-ray diffraction (XRD) spectrum. Differential thermal analyzer (DTA) results show two exothermic peaks for 8 h cryomilled powder as compared to that of powder milled for 1 h. The ignition temperature of prepared powder mixture also decreased due to gradual structural refinement. The activation energy was also calculated and correlated with the DTA and SEM results. The cryomilled Al-Ni powder is composed of fine Al-Ni metastable junctions which improve the reactivity at a lower exothermic reaction temperature.

show abstract

“…One of the most serious problems during such processing turned out to be a sticking of the milled materials to the walls of vials used for this purpose, which could be alleviated through the addition of stearic acid or alcohol (process control agent, PCA). As in the case of some materials like Ti, Ni, or Al, accumulation of milled powders on the milling container walls was found to be quite heavy [17,18], so it could be accepted as an alternative deposition method of coatings. Papers in this area published so far describe such a possibility as the formation of coatings by mechanical alloying [8,9,10,11,12], mechanical milling [13,19] or mechanical attrition treatment [20,21].…”

Section: Discussionmentioning

confidence: 99%

Microstructure of Coatings on Nickel and Steel Platelets Obtained by Co-Milling with NiAl and CrB2 Powders

et al. 2019

View full text Add to dashboard Cite

Metal matrix composite coatings are developed to protect parts made from materials susceptible to wear, like nickel alloys or stainless steel. The industry-established deposition method is presently an atmospheric plasma spraying method since it allows the production of both well-adhering and thick coatings. Alternatively, similar coatings could be produced by co-milling of ceramic and alloyed powders together with metallic plates serving as substrates. It results in mechanical embedding of the powder particles into exposed metallic surfaces required coatings. The present experiment was aimed at the analysis of microstructure of such coatings obtained using NiAl and CrB2 powders. They were loaded together with nickel and stainless steel platelets into ball mill vials and rotated at 350 rpm for up to 32 h. This helped to produce coatings of a thickness up to ~40 µm. The optical, scanning, and transmission electron microscopy observations of the coatings led to conclusion that the higher the rotation speed of vials, the wider the intermixing zone between the coating and the substrate. Simultaneously, it was established that the total thickness of the coating deposited at specified conditions is limited by the brittleness of its nanocrystalline matrix. An increase in the hardness of the substrate results in a decrease of the intermixing zone. The above results indicate that even as the method based on mechanical embedding could so far produce thinner coatings than the plasma spraying, in the former case they are characterized by a more uniform nanocrystalline matrix with homogenously distributed fine ceramic particles.

show abstract

Combustion of mechanically activated Ni/Al reactive composites with microstructural refinement tailored using two-step milling

Cited by 25 publications

References 34 publications

Microscopic two-color infrared imaging of Ni Al reactive particles and pellets

Microscopic two-color infrared imaging of Ni Al reactive particles and pellets

Exothermic Reaction Kinetics in High Energy Density Al-Ni with Nanoscale Multilayers Synthesized by Cryomilling

Microstructure of Coatings on Nickel and Steel Platelets Obtained by Co-Milling with NiAl and CrB2 Powders

Contact Info

Product

Resources

About