Abstract: The present invention discloses a forming device for a large thin-walled part with a curved surface, which includes a punch, a blank holder, a die, a lower die plate, a first annular sleeve and second annular sleeves. The first annular sleeve is connected with first driving oil cylinders. An inner diameter of the die is greater than an outer diameter of the punch. The first annular sleeve is arranged in a gap between the punch and the die. The second annular sleeve is arranged at the bottom of the punch. The first annular sleeve is arranged outside the second annular sleeve. The second annular sleeve is connected with second driving oil cylinders. The first driving oil cylinders and the second driving oil cylinders are connected with a hydraulic system.

Abstract: The present invention discloses a forming device for a large thin-walled part with a curved surface, which includes a punch, a blank holder, a die, a lower die plate, a first annular sleeve and second annular sleeves. The first annular sleeve is connected with first driving oil cylinders. An inner diameter of the die is greater than an outer diameter of the punch. The first annular sleeve is arranged in a gap between the punch and the die. The second annular sleeve is arranged at the bottom of the punch. The first annular sleeve is arranged outside the second annular sleeve. The second annular sleeve is connected with second driving oil cylinders. The first driving oil cylinders and the second driving oil cylinders are connected with a hydraulic system.

Abstract: Disclosed is a composite abrasive with hard core and soft shell, comprising hard abrasive core with grain diameter in a range of 0.1˜1 ?m and a soft oxide shell with thickness in a range of 5˜100 nm, the grain size of the oxide of the soft oxide shell is in a range of 5˜20 nm, the composite abrasive is obtained from aqueous solution of oxide inorganic salt precursor and the hard abrasive by dispersing, constant temperature reflux hydrolyzing, solid-liquid separating, washing and drying. The component abrasive with hard core and soft shell of the present invention can improve the manufacturing efficiency and the surface quality during the ultraprecise manufacturing of the sapphire substrate.

Abstract: Disclosed is a composite abrasive with hard core and soft shell, comprising hard abrasive core with grain diameter in a range of 0.1˜1 ?m and a soft oxide shell with thickness in a range of 5˜100 nm, the grain size of the oxide of the soft oxide shell is in a range of 5˜20 nm, the composite abrasive is obtained from aqueous solution of oxide inorganic salt precursor and the hard abrasive by dispersing, constant temperature reflux hydrolyzing, solid-liquid separating, washing and drying. The component abrasive with hard core and soft shell of the present invention can improve the manufacturing efficiency and the surface quality during the ultraprecise manufacturing of the sapphire substrate.