Analysis and Control of Cracks in Ni60 Coating of 7050 Aluminum Alloy by Electron Beam Cladding

Ni60 electron beam cladding can play an important role in improving the properties of 7050 aluminum alloy. The cracking of the cladding layer, however, greatly affects the cladding quality. To solve this problem, the optimum range of cladding process parameters is determined by an experimental method: electron beam current [25–30 × 10−3 A], scanning speed [10–12 mm/s] and focusing current [700–720 × 10−3 A]. Through range analysis of the experiment results, the primary and secondary order of the influence of the cladding process parameters on the crack areal density is determined as follows: electron beam current > scanning speed > focusing current. A mathematical model of the crack areal density of the cladding layer is established based on the method of nonlinear regression, which is y = 4.1553 × 104 I2.2887V−0.8379I210.2675. It is shown that the model has obvious significance in the results of variance analysis, which can provide a basis for the selection of electron beam cladding process parameters.