US 12,449,376 B2
Method for evaluating substrate surface cleanliness oriented to additive forging
Jiang Guo, Liaoning (CN); Renke Kang, Liaoning (CN); Zhaocheng Wei, Liaoning (CN); Yong Zhao, Liaoning (CN); Bin Xu, Liaoning (CN); Zhuji Jin, Liaoning (CN); and Dianzhong Li, Liaoning (CN)
Assigned to DALIAN UNIVERSITY OF TECHNOLOGY, Liaoning (CN); and INSTITUTE OF METAL RESEARCH, CHINESE ACADEMY OF SCIENCES, Liaoning (CN)
Appl. No. 18/247,461
Filed by DALIAN UNIVERSITY OF TECHNOLOGY, Liaoning (CN); and INSTITUTE OF METAL RESEARCH, CHINESE ACADEMY OF SCIENCES, Liaoning (CN)
PCT Filed Jan. 20, 2022, PCT No. PCT/CN2022/072970
§ 371(c)(1), (2) Date Mar. 31, 2023,
PCT Pub. No. WO2022/156744, PCT Pub. Date Jul. 28, 2022.
Claims priority of application No. 202110093916.6 (CN), filed on Jan. 22, 2021.
Prior Publication US 2024/0003824 A1, Jan. 4, 2024
Int. Cl. G01N 21/94 (2006.01)
CPC G01N 21/94 (2013.01) [G01N 2021/945 (2013.01)] 1 Claim
OG exemplary drawing
 
1. A method for evaluating surface cleanliness of metal substrate for additive forging, comprising the following steps:
step 1: determining contaminants on surface of the metal substrate,
which comprises:
machining a sample smaller than the metal substrate using same milling parameters used in machining the metal substrate, examining a plurality of surface areas of the sample using an X-ray energy spectrum analyzer in a surface scanning mode and an ultra-depth-of-field microscope, and then determining types of surface contaminants according to the compositions and appearance characteristics obtained by the X-ray energy spectrum analyzer and by the ultra-depth-of-field microscope,
wherein the contaminants include oil contaminants, particles, and chips;
step 2: determining weight coefficients of the contaminants, which comprises:
assigning weight coefficients of oil contaminants, particles and chips are expressed as WC1, WC2 and WC3, respectively, and wherein WC1+WC2+WC3=1, wherein a weight coefficient corresponds to a degree of hindrance on interface bonding of the substrate,
wherein WC1 is between 0.5 and 0.7, WC2 is between 0.2 and 0.4, and of WC3 is between 0.0 and 0.2;
step 3: determining a contamination score of each contaminate,
selecting a measurement area on the surface of the metal substrate, determining the contamination score of oil contaminant g1, using a water droplet contact angle method; and determining the contamination score of particles g2 and the contamination score of chips g3 using an optical observation method;
wherein,
the water droplet contact angle method comprises: comparing an average value of left contact angle and an average value of right contact angle of the water droplet with a reference value to determine a contamination point; performing 10 water droplet contact tests in total in 10 different areas on the surface of the metal substrate, and obtaining the contamination score g1 that equals to a ratio of the number of contamination points to the number of total measurement points;
the optical observation method comprises: determining a number of particles and a number of chips using the optical observation method, respectively, and obtaining the contamination score g2 and the contamination score g3 by dividing the number of particles and the number of chips by 10, respectively; and
step 4: determining a cleanliness level, which comprises:
selecting a cleanliness level according to the contamination score L, wherein the contamination score L is determined by

OG Complex Work Unit Math
wherein
Cleanliness Level I indicates an ideal clean state, and L=0;
Cleanliness Level II indicates a clean state, and 0<L≤0.25;
Cleanliness Level III indicates a general clean state, and 0.25<L≤0.50;
Cleanliness Level IV indicates a state of slight contamination, and 0.50<L≤0.75;
Cleanliness Level V indicates a state of contamination, and 0.75<L≤1.00; and
Cleanliness Level VI indicates a state of heavy contamination, and L>1.00.