A 3-DIMENSIONAL MODEL OF THE SPRAY FORMING METHOD

A three-dimensional model has been formulated to calculate the shape o f the general preform, using vector calculus. The shape of a rod, tube , plate, or irregular preform can be calculated at given spray forming conditions. The shape of a spray-formed rod was analyzed at various s pray forming conditions using the three-dimensional model. The effects of spray forming parameters, such as spray distribution parameters, a ngular velocity of rotation, withdrawal velocity, spray angle, and ecc entric distance on rod shape, were analyzed. The most important parame ters affecting the shape of rods are the spray distribution parameters and the withdrawal velocity. The dynamic evolution of rod shape with a stepwise variation of the withdrawal velocity during spray forming w as investigated. The effect of a stepwise change of the withdrawal vel ocity was the same as that of the scanning atomizer. The calculated su rface profiles were compared with those of spray-formed 7075 aluminum alloy rods prepared on a pilot scale. The calculated results for the s urface profiles were in agreement with those of the spray-formed rods.