Development of microstructure in spray formed alloys

Cantor, B.; Baik, Kyeong Ho; Grant, Patrick S.

doi:10.1016/s0079-6425(97)00033-9

Cited by 34 publications

(21 citation statements)

References 11 publications

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“…The trade-off between the enthalpy input rate from deposited droplets at the top surface, and the enthalpy removal rate (both by conduction to the substrate or to any previously deposited material, and by convection to the gas surrounding the deposit) is a critical factor in this respect ( Ref 5,6,10,14,25). It becomes necessary, therefore, to determine how much the temperature actually changes on the top surface of the coating when a Cu-Al alloy, is added as bond coat in a composite system.…”

Section: Discussionmentioning

confidence: 99%

“…The coating is deposited in several passes, each pass involving the transfer of many individual droplets and semi-molten or even solid particles, which impinge on the surface of the substrate or a previously deposited layer. The mechanisms associated with this type of deposition, involve a wide range of physical processes (Ref [5][6][7][8][9][10], and the operational parameters must be carefully controlled in order to obtain the desired microstructure in the final coating ( Ref 3,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

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An Alternative Cu-Based Bond Layer for Electric Arc Coating Process

et al. 2011

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A Cu-Al alloy has been used as bond coat between a carbon steel substrate and a final coating deposit obtained by applying the twin wire electric arc spraying coating technique. The presence of a copperbased material in the composite system can change the overall temperature profile during deposition because copper exhibits a thermal conductivity several times higher than that of the normally recommended bond coat materials (such as nickel-aluminum alloys or nickel-chromium alloys). The microstructures of 420 and 304 stainless steels deposited by the electric arc spray process have been investigated, focusing attention on the deposit homogeneity, porosity, lamellar structure, and microhardness. The nature of the local temperature gradient during deposition can strongly influence the formation of the final coating deposit. This study presents a preliminary study, undertaken to investigate the changes in the temperature profile which occur when a Cu-Al alloy is used as bond coat, and the possible consequences of these changes on the microstructure and adhesion of the final coating deposit. The influence of the thickness of the bond layer on the top coating temperature has also been also evaluated.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Alternative Cu-Based Bond Layer for Electric Arc Coating Process

et al. 2011

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“…We assume that all the a-Al 15 (Fe,TN) 3 Si 2 phases can be formed via peritectic transformation, or, the peritectic transformation can be suppressed by high cooling rate, in that way, the dAl(Fe,TN)Si phase in atomized droplets will be further refined through the strong collision and fragmentation between atomized droplets or particles and the surface of the as-deposited preforms [27]. Then the high temperature annealing in the mushy zone [44][45][46] or the low cooling rate (<10 K/s) within the asdeposited preforms [44,46,47] …”

Section: Discussion Of the Phase Transformation And Microstructural Fmentioning

confidence: 99%

“…The rapid solidification techniques can increase the cooling rate and nucleation rate so as to refine the microstructures [25][26][27], for instance, Rapid Solidification Powder Metallurgy process (RS/PM) [5,[28][29][30] and SF technique [26,27,31,32] have been applied to prepare hypereutectic Al-Si alloys in the past decades. Hypereutectic Al-Si alloys, such as Al-Si-Fe, Al-SiFe-Cu, Al-Si-Fe-Cu-Mg etc., prepared by SF process, are characterized by fine and uniform microstructures [27,[31][32][33], but our research [34] shows that their thermal stability and high temperature strength cannot satisfy the performance requirements of materials used for engine cylinder liners located in high temperature-pressure conditions. Introducing Mn elements can modify the needlelike Fe-bearing phases into highly thermal stable aAl(Fe,Mn)Si phase, contributing to enhance the thermal stability and high temperature strength [32].…”

Section: Introductionmentioning

confidence: 99%

Microstructure modification and related mechanism of spray‐formed Fe‐bearing hypereutectic Al‐Si alloys

Hou

Cai

Cui

et al. 2010

Materialwissenschaft Werkst

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The Fe-bearing hypereutectic Al-Si alloys with/without Cr/(Cr+Mn) addition have been prepared by Spray Forming (SF) process. With 2 wt.% Cr addition, the short-rod b-Al 5 FeSi phase in sprayformed Al-25Si-5Fe-3Cu (wt.%, denoted as 3C) alloy can be substituted by particulate aAl(Fe,Cr)Si phase with sizes less than 5 -6 lm. But small quantity of blocky b-Al 5 (Fe,Cr)Si phase still appears in Cr-added hypereutectic Al-Si alloy. When (2Cr+1Mn) (wt.%) are added simultaneously into 3C alloy, almost all the short-rod b-Al 5 FeSi phase or blocky b-Al 5 (Fe,Cr)Si phase disappear, instead, the a-Al(Fe,Cr,Mn)Si phase become the only Fe-bearing phase. During heat treatments, the other two spray-formed hypereutectic Al-Si alloys (besides SF-3C alloy) are thermodynamically stable for the appearance of high thermodynamically stable particulate aAl(Fe,Cr)Si/a-Al(Fe,Cr,Mn)Si phase. Also the phase transformation occurred during the heating/ cooling process of the present hypereutectic Al-Si alloys are investigated and the mechanism of microstructural formation of the spray-formed alloys are discussed.Keywords: Spray Forming / hypereutectic Al-Si alloy / microstructure / thermal stability / phase transformation / Schlüsselwörter: Sprühkompaktieren / hypereutektische Al-Si-Lebierung / thermische Stabilität / Phasenumwandlung /

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“…Spray forming offers a new approach to resolve the deformation difficulties for superalloys. Spray forming gives the advantages of producing finer grain size, distributing the precipitates more uniformly in the matrix, eliminating macrosegregation and reducing microsegregation of alloying elements (Grant, 1995;Cantor et al, 1997;Lavernia and Wu, 1996). In recent years, a lot of investigations on deformation behaviors of spray formed aluminum alloys, magnesium alloys, high-speed steels and superalloys have been carried out Rodenburg et al, 2004;Chen and Chi, 2004;Li et al, 2004).…”

Section: Introductionmentioning

confidence: 99%