Research on microstructure and mechanical properties of Ta1/4J33 laser-welded joints

The melting point of tantalum is 2996°C and 4J33 melting point difference of about 1500°C, it is difficult to connect them firmly by traditional welding method. Using laser welding method, the orthogonal test method is selected to design the welding test scheme for three influencing factors; power, rotation speed and offset. According to the range calculation, it is determined that power has the greatest influence on the melting depth, followed by offset, and rotation speed has the least influence. The optimal welding parameters are determined: power is 240W, rotating speed is 3.0s/r, and offset is 0.18 mm. Metallographic analysis shows that there are no visible cracks, burning through and pores on the surface of the joint. The proportion of 4J33 alloy in the welding seam is greater than that of tantalum. the element Ta1 diffuses and interacts with the 4J33 alloy, forming intermetallic compounds.