Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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The Study of Curing Day Reduction by Step Curing of HTPB/AP Propellant

HTPB/AP계열의 고체 추진제의 Step 경화 방법을 통한 경화일(기간) 단축

  • Received : 2020.09.09
  • Accepted : 2020.10.16
  • Published : 2020.12.31
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Abstract

In this paper, step-curing, which includes the change of curing temperature on the curing process, was applied to reduce curing day of HTPB/AP based propellant. This study targets the improvement of productivity of HTPB/AP based solid rocket motor. Comparison of mechanical properties of propellant resulted in the change of normal curing condition (60℃, 5 days) to step-curing condition (60℃, 1 day / 65℃, 3 days). Post-cure test was conducted to determine the impact on the shelf life of the solid rocket motor. The aging characteristics of propellants were analyzed by measuring mechanical properties and thermal expansion factor. To step-cured propellant, accelerated aging test was performed for 12 weeks, followed by tensile test. Sm(bar) and Em(%) were higher than 8 bar and 40% each, showing excellent mechanical properties.

본 논문에서는 HTPB/AP 계열의 추진제의 경화 온도를 변화시키는 Step 경화 방법으로 경화일 단축 연구를 진행하였다. 이 연구는 HTPB/AP 계열의 추진기관 제작 시 생산성 향상(제작기간 단축 및 치구회수율 증대)을 목적으로 한다. 정상 경화 대비 추진제의 기계적 물성을 비교하여 정상 경화 시 60℃ 5일 소요되는 경화일을 Step 경화로 4일(60℃ 1일 / 65℃ 3일)로 설정하였다. 경화일 단축을 적용 시 추진제 노화 특성을 알아보기 위해 Step 경화 후 후경화(Post-cure) 시험을 진행하였다. 이를 통해 기계적 물성 및 열팽창 계수를 측정하여 추진제의 후경화 특성을 분석하였다. 또한, Step 경화 후 가속 노화 시험을 진행하여 12주차 경과 후 인장시험을 수행하였다. 그 결과, Sm(bar)은 8 bar 이상, Em(%)은 40%이상으로 요구되는 우수한 기계적 물성을 가지는 것을 알 수 있었다.

Keywords

References

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