A green cleaning technology for blind hole remanufacturing blanks with supercritical n-butanol

This paper aims to solve the problem of incomplete cleaning for blind hole remanufacturing blanks and damaging the matrix material in the cleaning process, a novel cleaning method by supercritical n-butanol is proposed. The feasibility of cleaning blind hole remanufacturing blanks is verified, and the mechanism of supercritical n-butanol cleaning is analyzed. The surface cleanliness of matrix structure, the properties change of matrix material and the environmental impact of the cleaning process are explored. The results indicated that there were no contaminants on the surface of cleaned matrix structure under the temperature 300°C, pressure 5.5 MPa, and cleaning time 10 min. Hardness, yield strength and tensile strength of matrix material after cleaning could increase by approximately 14%, 8%, and 5%, respectively. Compared with subcritical water, the oxidation degree of matrix structure cleaned by supercritical n-butanol was lower. Compared with high-temperature cleaning, seven environmental indexes of supercritical n-butanol cleaning process decreased significantly. Supercritical n-butanol cleaning is an ideal choice for blind hole remanufacturing blanks.