Composition control for laser solid forming from blended elemental powders

Laser solid forming (LSF) from blended elemental powders is a powerful tool for the synthesis of novel materials. Accurate composition control is critical for the application of this technique. It is found that the chemical composition of as-deposited sample can be controlled the same as the premixed elemental powders by keeping the identity of the divergence angles of the elemental powder streams. A mathematical model was established to describe the powder delivery process during LSF from blended elemental powders. Based on the consistency condition for divergence angles of different elemental powder streams, the match condition among the elemental powder characteristics (including particle size and density) can be obtained, which ensures the consistency in composition between the laser deposits and the premixed elemental powders. LSF experiments were carried out using a blend of Ti, Al, and V powders and the composition analysis was performed on as-deposited samples. The experimental results demonstrate the validity of the developed mathematical model.