Burning Rate Studies of Metal Powder (Ti, Ni)–Based Fuel-Rich Propellants

This paper reports the burning rate results of titanium (Ti) and nickel (Ni)–based fuel-rich propellants with hydroxyl terminated polybutadiene (HTPB) and double-base (DB) matrix as binder. The results are discussed in comparison to aluminum (Al) and zirconium (Zr)–based formulations studied earlier by the authors. While 20% Ti containing composition with HTPB as binder gave burning rates comparable to those of aluminized formulation, superior burning rates were obtained for Ti-based formulations with higher metal loading (30–60%). 50–60% Ti-containing compositions gave higher burning rates than those for even zirconium (Zr)–based formulations. Fuel-rich formulations with a DB matrix produced much higher burning rates than corresponding HTPB-based compositions in the pressure range of 3.4–8.8 MPa. In these systems, Ti-incorporating formulations exhibited higher burning rates than aluminized compositions and lower than those for Zr compositions. Interestingly, Ni propellants gave burning rates close to those for Ti-based compositions and exhibited superior combustion characteristics in lower pressure ranges in systems with a DB matrix. Formulations with a GAP plasticized DB matrix exhibited 2–3 times higher burning rates than corresponding DEP plasticized compositions.