Method for evaluating substrate surface cleanliness oriented to additive forging

Patent metadata

Field	Value
Publication number	US-12449376-B2
Application number	US-202218247461-A
Country	US
Kind code	B2
Filing date	Jan 20, 2022
Priority date	Jan 22, 2021
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A method for evaluating a surface cleanliness oriented toward additive forging of a metal substrate employs weight coefficients corresponding to oil contaminants, particles and chips. Contamination scores of different contaminants are determined separately by different methods, and a surface cleanliness thereof is characterized in a quantitative manner by calculating the sum of the product of the weight coefficient and the contamination score of each contaminant. Further, an accurate and systematic method for evaluating a surface cleanliness employs weight coefficient of each contaminant determined based on a degree of adverse influence of the contaminant on the interface bonding of a substrate. Different detection methods are used for different contaminants. The contamination score of each contaminant is determined by the sum of the product of the weight coefficient and the contamination score of the corresponding contaminant, the comparison relationship is thus established, a cleanliness level is finally determined.

First claim

We claim:

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 WC 1 , WC 2 and WC 3 , respectively, and wherein WC 1 +WC 2 +WC 3 =1, wherein a weight coefficient corresponds to a degree of hindrance on interface bonding of the substrate,
wherein WC 1 is between 0.5 and 0.7, WC 2 is between 0.2 and 0.4, and of WC 3 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 g 1 , using a water droplet contact angle method; and determining the contamination score of particles g 2 and the contamination score of chips g 3 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 g 1 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 g 2 and the contamination score g 3 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

L
=

∑

i
=
1

i
=
3

W
⁢

C
i

×

g
i

(
1
)

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.

Assignees

• Univ Dalian Tech
• Inst Metal Research Cas

Inventors

• Guo Jiang
• Kang Renke
• Wei Zhaocheng
• Zhao Yong
• Xu Bin
• Jin Zhuji
• Li Dianzhong

Classifications

• G01N2021/945

  Liquid or solid deposits of macroscopic size on surfaces, e.g. drops, films, or clustered contaminants · CPC title

• G01N21/94 Primary

  Investigating contamination, e.g. dust (G01N21/85 takes precedence) · CPC title