Coarse-grained heat-affected zones

Metallographic studies showed a continuous net of eutectic precipitations in the weld metal along the grain boundaries of the a-solid solution of copper in aluminum. Their coarse accumulations were also discovered in the heat-affected zone (HAZ) near the fusion line [ ]. 

The laser deposition process epitaxially generates coarse columnar crystals, and laser remelting reduces the microhardness of the selective laser melting substrate in the 2 mm to 3 mm thick grain increased heat affected zone (31). 

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