Microstructure evolution mechanism of single and multi-pass in laser cladding based on heat accumulation effect for invar alloy

As in various manufacturing processes, in sliding tests with scanning motions to extend the sliding distance over fresh countersurface, temperature rise during any pass is bolstered by heating during prior passes over neighboring tracks, providing a “heat accumulation effect” with persisting temperature rises contributing to an overall temperature rise of the current pass. Conduction modeling is developed for surface temperature rise as a function of numerous inputs: power and size of heat source; speed and stroke length, and track increment of scanning motion; and countersurface thermal properties. Analysis focused on mid-stroke location for passes of a square uniform heat flux sufficiently far into the rectangular patch being scanned from the first pass at its edge that steady heat accumulation effect response is adopted, focusing on maximum temperature rise experienced across the pass' track. The model is non-dimensionalized to broaden the applicability of the output of its runs. Focusing on practical “high” scanning speeds, represented non-dimensionally by Peclet number (in excess of 40), applicability is further broadened by multiplying non-dimensional maximum temperature rise by the square root of Peclet number as model output. Additionally, investigating model runs at various non-dimensional speed (Peclet number) and reciprocation period values, it appears these do not act as independent inputs, but instead with their product (non-dimensional stroke length) as a single independent input. Modified maximum temperature rise output appears to be a function of only two inputs, increasing with decreasing non-dimensional values of stroke length and scanning increment, with outputs of models runs summarized compactly in a simple chart.

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Design and characterization on microstructure evolution and properties of laser-cladding Ni1.5CrFeTi2B0.5Mox high-entropy alloy coatings

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2020.126793 ◽

2021 ◽

pp. 126793

Author(s):

Zhen Gu ◽

Wenshan Peng ◽

Weimin Guo ◽

Yi Zhang ◽

Jian Hou ◽

...

Keyword(s):

Laser Cladding ◽

Microstructure Evolution ◽

High Entropy Alloy ◽

High Entropy

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Microstructure evolution and high-temperature tribological behavior of Ti3SiC2 reinforced Ni60 composite coatings on 304 stainless steel by laser cladding

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2021.127335 ◽

2021 ◽

pp. 127335

Author(s):

Yi-Fan Liu ◽

Su-Guo Zhuang ◽

Xiu-Bo Liu ◽

Chun-Sheng OuYang ◽

Yang Zhu ◽

...

Keyword(s):

Stainless Steel ◽

High Temperature ◽

Laser Cladding ◽

Microstructure Evolution ◽

Tribological Behavior ◽

Composite Coatings ◽

304 Stainless Steel

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Review on Relationships of Temperature History, Fatigue Damage and Microstructure Evolution Mechanism of Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.584-586.944 ◽

2014 ◽

Vol 584-586 ◽

pp. 944-950 ◽

Cited By ~ 1

Author(s):

Dong Fu Zhao ◽

Mei Liu ◽

Shi Ji Zhang

Keyword(s):

High Temperature ◽

Fatigue Damage ◽

Microstructure Evolution ◽

Research Direction ◽

Concrete Research ◽

Temperature History ◽

Evolution Mechanism ◽

Main Research ◽

High Temperature Process ◽

Application Prospects

The domestic and overseas research progresses of microstructure of the concrete and fatigue damage after treated by high temperature are reviewed. The main research direction and current shortage on the high temperature process, fatigue damage and the microstructure evolution mechanism of concrete are discussed. A view of the application prospects of concrete research on the high temperature process, fatigue damage and the microstructure evolution mechanism of concrete is forecast.

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Parameter optimisation of laser cladding repair for an Invar alloy mould

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405418805653 ◽

2018 ◽

Vol 233 (8) ◽

pp. 1859-1871 ◽

Cited By ~ 6

Author(s):

Shichao Zhu ◽

Wenliang Chen ◽

Xiaohong Zhan ◽

Liping Ding ◽

Junjie Zhou

Keyword(s):

Dilution Rate ◽

Laser Cladding ◽

Laser Power ◽

Scanning Speed ◽

Advanced Technology ◽

Invar Alloy ◽

Geometric Features ◽

Feeding Rates ◽

Cladding Layer ◽

Powder Feeding

Laser cladding repair is an advanced technology for repairing Invar alloy moulds; however, the influences of various processing parameters on the quality of the Invar alloy moulds have yet to be determined. To explore the optimisation of laser cladding repair parameters, analyses of the geometric features and microstructure of the cladding layer were conducted. First, the influences of different powder feeding rates and scanning speeds on the dilution rate of the substrate were investigated by establishing a mathematical model of the laser power attenuation. Next, the influences of the parameters on the geometric features of the cladding layer were analysed. Finally, the influences of the parameters on the microstructure of the cladding layer were evaluated. At a laser power of 2300 W, a scanning speed of 3 m/min, and a powder feeding rate of 9 g/min, the best results of the width, height, dilution rate, roughness, and contact angle of the cladding layer were obtained. The results of this study indicated that excellent metallurgical bonding occurred between the cladding layer and the interface layer, and that the intended geometric features and desired microstructure of the cladding layer were obtained.

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