Study On Low Infrared Emissivity Materials Of Aluminum-Chrome Phosphates Matrix

The continuous progress of infrared stealth technology has made the development of infrared stealth materials faster and faster.As the key of infrared stealth technology,low infrared emissivity material occupies a very important position.Therefore,the study of low infrared emissivity materials and its affecting factors is of great significance to the development of stealth materials.In this paper,low infrared emissivity materials of aluminum-chrome phosphates matrix were prepared by using ordinary aluminum powder,spherical aluminum powder and flake aluminum powder as fillers and aluminum-chrome phosphates?ACP?as a binder.The affecting factors of its infrared emissivity and bond strength as well as the phase and structure changes at high temperatures were studied and the following results were obtained:A low infrared emissivity material of ordinary aluminum-aluminum-chrome phosphates matrix is prepared by using ordinary aluminum powder as a filler and ACP as a binder.The infrared emissivity decreases with the increasing content of the ordinary aluminum powder,and the optimal addition amount of ordinary aluminum powder is 30wt%,and the corresponding infrared emissivity is 0.68.After curing at 160°C for 3 h,the bond strength is the best and reaches 1.92 MPa.Ordinary aluminum-aluminum-chrome phosphates has good high temperature resistance and thermal stability.When the temperature is lower than 1000°C,the aluminum-chrome phosphates matrix is mainly amorphous.But at 1200°C,the main crystal forms are AlPO₄,Al₂O₃ and trace amounts of Al,Al?PO₃?₃ and Cr?PO₃?₃.A low infrared emissivity material of spherical aluminum-aluminum-chrome phosphates matrix is obtained by using spherical aluminum powder as a filler and aluminum-chrome phosphates as a binder.The infrared emissivity decreases with the increasing content of spherical aluminum powder,and the optimal addition amount of spherical aluminum powder is 30 wt%,and the corresponding infrared emissivity is0.62.After curing at 160°C for 3 h,the bond strength is the best and reaches 2.34 MPa.Spherical aluminum-aluminum-chrome phosphates has good high temperature resistance and thermal stability.When the temperature is lower than 1000°C,the aluminum-chrome phosphates matrix is mainly amorphous.But at 1200°C,the main crystal forms are Al₂O₃ and trace amounts of AlPO₄.A low infrared emissivity material of flake aluminum-aluminum-chrome phosphates matrix is made by using flake aluminum powder as a filler and aluminum-chrome phosphates as a binder.The infrared emissivity decreases with the increasing content of flake aluminum powder,and the optimal addition amount of the flake aluminum powder is 30 wt%,and the corresponding infrared emissivity is 0.60.After curing at 160°C for 3 h,the bond strength is the best and reaches 2.15 MPa.Flake aluminum-aluminum-chrome phosphates has good high temperature resistance and thermal stability.When the temperature is lower than 1000°C,the aluminum-chrome phosphates matrix is mainly amorphous.But at 1200°C,the main crystal forms are AlPO₄,Al₂O₃ and trace amounts of Al,Al?PO₃?₃ and Cr?PO₃?₃.