Deep drawing and redrawing of solution-treated Cu-Cr-Zr-Ti alloy sheets and post-forming characterization of the redrawn cup wall

Recently, space research organizations are interested in investigating multistage deep drawing of Cu-Cr-Zr-Ti alloy sheets for the fabrication of large-depth thrust chamber liners used in cryogenic engine of satellite launch vehicles. Hence, an attempt was made for the first time to design and develop a laboratory scale two-stage deep drawing setup to successfully draw cylindrical cups of solution-treated Cu-0.5Cr-0.05Zr-0.05Ti (wt. %) sheets of 1.7 mm thickness. The finite element (FE) model with Marciniak-Kuczynski forming limit diagram (MK-FLD) was implemented to design the above two-stage deep drawing setup, and two different anisotropic models, namely Hill48 and Barlat89, along with solid and shell element formulations were used to capture the deformation behavior. After setup design, the two-stage deep drawing experiments were conducted, and successful redrawn cups with overall drawing ratio of 2.94 with maximum cup depth of 58.5 mm was achieved. The strain evolution during deformation was analyzed in polar effective plastic strain (PEPS) locus, and it was also observed that the surface roughness of cup wall and corner was significantly increased to 2.73 & mu;m and 3.16 & mu;m, respectively, due to accumulation of plastic strain and evolution of texture. Further, the orientation gradient inside the grains at both cup wall and corner regions was observed, and evolution of Copper {112} < 111> and Y{111} texture components were identified in the cup wall. However, the marginal increase in roughness of cup corner as compared to that of the cup wall might be due to the development of Brass {110} < 112 > texture. Finally, the aging behavior of redrawn cup wall was analyzed, and it was found that the peak aging occurred at 500 & DEG;C for 2 h. with a hardness of 98 & PLUSMN; 4 VHN due to the formation of fine Cr-rich precipitates.

Automated summary

Recently, a laboratory-scale two-stage deep drawing setup was designed and developed for the fabrication of large-depth thrust chamber liners used in satellite launch vehicles. The setup successfully drew cylindrical cups of Cu-Cr-Zr-Ti alloy sheets of 1.7 mm thickness. Finite element analysis was used to design the setup and capture the deformation behavior. Through experiments, cups with a maximum depth of 58.5 mm and increased surface roughness were achieved. The aging behavior of the redrawn cups was also analyzed, revealing the formation of fine Cr-rich precipitates at 500°C for 2 hours.