Non-destructive Quality Control Research Articles

THE HEAT TREATMENT EFFECT ON THE MAGNETOELASTIC SENSITIVITY OF HIGH-CHROMIUM STEEL TO LOW-CYCLE ELASTIC DEFORMATIONS IN THE MAGNETOELASTIC MEMORY MODE

The magnetoelastic tests’ results for the 30Kh13 steel samples hardened and tempered at different temperatures are presented. The samples premagnetized to saturation are treated to a fivescore-cycle stretching effect. It is followed by repetition with the load increase by 50 MPa. The magnetic field intensity of the residual magnetization is recorded synchronously with the active load. The high structural sensitivity of magnetoelastic irreversible demagnetization  = ∆H/∆σ in the low loads’ part is shown and explained. It allows using this parameter for non-destructive quality control of steels with properties close to 30Kh13 and the same composition products. Samples with a high tempering temperature of 600...700 С make it possible to create peak (limit) load sensors and fatigue damage sensors on their basis. It is proposed to use them in the form of glued foil or wire elements that can work off-line.

Application of Multispectral Camera in Monitoring the Quality Parameters of Fresh Tea Leaves

The production of high-quality tea by Camellia sinensis (L.) O. Ktze is the goal pursued by both producers and consumers. Rapid, nondestructive, and low-cost monitoring methods for monitoring tea quality could improve the tea quality and the economic benefits associated with tea. This research explored the possibility of monitoring tea leaf quality from multi-spectral images. Threshold segmentation and manual sampling methods were used to eliminate the image background, after which the spectral features were constructed. Based on this, the texture features of the multi-spectral images of the tea canopy were extracted. Three machine learning methods, partial least squares regression, support vector machine regression, and random forest regression (RFR), were used to construct and train multiple monitoring models. Further, the four key quality parameters of tea polyphenols, total sugars, free amino acids, and caffeine content were estimated using these models. Finally, the effects of automatic and manual image background removal methods, different regression methods, and texture features on the model accuracies were compared. The results showed that the spectral characteristics of the canopy of fresh tea leaves were significantly correlated with the tea quality parameters (r ≥ 0.462). Among the sampling methods, the EXG_Ostu sampling method was best for prediction, whereas, among the models, RFR was the best fitted modeling algorithm for three of four quality parameters. The R2 and root-mean-square error values of the built model were 0.85 and 0.16, respectively. In addition, the texture features extracted from the canopy image improved the prediction accuracy of most models. This research confirms the modeling application of a combination of multi-spectral images and chemometrics, as a low-cost, fast, reliable, and nondestructive quality control method, which can effectively monitor the quality of fresh tea leaves. This provides a scientific reference for the research and development of portable tea quality monitoring equipment that has general applicability in the future.

Chemical Current Source Express Diagnostics Using Noise Spectroscopy on the Example of Lithium-Thionyl Chloride Battery

Lithium-thionyl chloride battery voltage is practically not changing during the discharge process and drops sharply being completely discharged. In this regard, the problem of non-destructive quality control of the chemical current sources (first of all, the discharge degree) before installation thereof in the equipment becomes of particular importance. Microcalorimetric studies make it possible to rather correctly determine the current source internal self-discharge rate, predict the LCCS shelf life and its performance term. However, the heat release absolute value in current sources with sufficient storability, i.e., with low self-discharge, is very small; therefore, it is necessary to use sensitive, stationary and large-sized equipment. This makes such diagnostics impossible when operating in the stand-alone conditions. The impedance spectroscopy method could be proposed to solve this problem. However, satisfactory results are only obtained in the 0--70 % residual capacitance range. Determination of residual capacitance in the 70--100 % range appears to be rather difficult due to the absence of noticeable alteration in the informative parameter within the limits of its absolute deviation from the mean value. In this regard, it looks advisable to use noise spectroscopy as a physically independent method in diagnosing the state of chemical current sources to expand the residual capacitance diagnostics range to the 70--100 % domain, as well as to increase reliability of the chemical current source diagnostic estimate in the range of 50--70 %. Results of the electrochemical noise measurement analysis confirm promising application of the noise spectroscopy method in estimating current state of the primary chemical current sources in their low discharge domains

Diagnosis of injection-molded weld lines in ABS thermoplastic by polarized terahertz reflective imaging

We carry out a nondestructive study of injection-mold weld lines in an acrylonitrile butadiene styrene (ABS) thermoplastic electrical receptacle plate. Terahertz techniques show morphological features at the weld lines and reveal terahertz birefringence properties localized around the welds, indicating frozen-in molecular orientation and stress proximate to the welds. Surface acoustic microscopy corroborates the morphological features at the welds shown by terahertz imaging and also reveals anomalous mechanical properties at the weld lines. These results indicate that THz-based techniques provide nondestructive reliability assessment and quality control for injection-molded thermoplastic products.

Автоматизована система безконтактного ультразвукового неруйнівного контролю якості корпусів ракетних двигунів твердого палива з композиційних матеріалів

Currently, in various industries (engineering, aircraft, energy, etc.) the issue of product quality assurance and control is particularly acute. This is due primarily to the ever-increasing requirements for increasing reliability with increasing loads on products, which entails the strengthening of technical standards. The issue of quality control for rocket and space technology products is especially relevant. Modern power structures of rocket and spacecraft made of polymer composite materials, and especially the body of solid fuel rocket engines (SFRЕ), are multilayer packages of various polymer-composite materials (PKM), obtained and interconnected in the process of manufacturing the body. The efficiency of SFRЕ depends on the quality of the formation of PKM in production conditions. The most important issues are the implementation of production quality control of composite structures, the reliability of control results and the ability to automate the control process. The article presents an automated system of non-contact ultrasonic non-destructive testing, which allows to control the stability of the technological process of forming the composite material of the wall of the SFRЕ body and, if necessary, to adjust it. The probability of detecting zones of anomalous violation of the integrity of the wall material of the SFRЕ housing is carried out due to adaptive algorithms, digital systems of multilevel matrix processing and optimal filtering of the received signals. The automated system of contactless ultrasonic non-destructive quality control of SFRЕ cases allows to register conditions of scanning and control for more visual representation of the defectogram in the expanded look of the case of a product in the course of control and at documentation of its results. The presented results of work on the development of an automated system of non-destructive testing of the integrity of the buildings of the SFRЕ type "cocoon" confirm the possibilities of practical implementation in production.

РОЗРОБКА МЕТОДУ НЕРУЙНІВНОГО КОНТРОЛЮ ЯКОСТІ ЗАГАРТОВАНИХ ГІЛЬЗ ЦИЛІНДРІВ АВТОТРАКТОРНОЇ ТЕХНІКИ

The main part of tractor engines is the cylinder liner, which depends on the life of the machine as a whole. It is made of gray cast iron (SCh20 DSTU 1412-85) with the addition of alloying elements and subjected to the working surface of HDTV hardening. Now quality control is carried out by destructive methods (assessment of hardness, durability, structure) on specially cut templates on 1 piece. from a party to 80-100 pieces of each melting. Such control does not ensure the reliability of products, both in the quality of the base metal and heat treatment. The solution to this problem is possible by developing non-destructive quality control of each product in different periods of the process process with assessment of the properties and stress level of both the base metal (corresponding to the outer surface) and the hardened layer (inner working surface). The intensity of cylinder wear depends on the conditions of friction of the cylinder-piston ring, which are affected by the design features of the engine (power, speed, compression ratio, cooling system, as well as fuel supply and combustion, air and oil purification system), quality of fuel and oil, operating conditions and wear resistance of the cylinder material. Wear of cylinders during friction paired with a piston ring during engine operation occurs as a result of a combination of many processes occurring simultaneously: destruction of microprojections of surfaces that are destroyed by repeated plastic deformation during engagement, as well as the destruction of tired origin; setting of the material of the microprojections with subsequent deep tearing of the metal particles during the destruction of the setting unit; accumulation of abrasive particles that contribute to the intensification of wear; abrasive action of dust particles, contribution products, solid inclusions on the surface of collapsing bodies; chemical corrosion under the influence of high temperatures of gaseous products of fuel combustion; electro-chemical corrosion from the action of acids formed during the dissolution of gaseous products in condensed water vapor on the walls of the cylinders.

Ultrasonic non-destructive quality control of products made of polymeric composite materials rocket and space equipment

The development of modern rocket and space technology (RST) is characterized by constant improvement: increasing speed, range and altitude. Improving these characteristics, through modernization, has led to a significant complication of the design of RST and its equipment. Among the most promising materials for the manufacture of RST structures are more often used polymer composite materials (PCM), which are increasingly used in modern RST engineering, especially in cases where no other material meets the new requirements. Quality control of RST products depends on determining the condition of materials in these facilities, both in production and in operating conditions, which must be carried out both in the production process (with the deviation of production processes may form different types of structure heterogeneity: porosity, foreign inclusions, stratification and cracks) and during operation. In polymer composite materials RST, namely to detect defects such as delamination and cracks using ultrasonic non-destructive testing. An analysis of the use of traditional ultrasonic non-destructive testing using a portable ultrasonic flaw detector using high-frequency transducers. It has been determined that it is sufficient to use portable ultrasonic flaw detectors to detect longitudinal cracks or stratifications, but for more reliable detection and detection of defects, completeness of control should use automated ultrasonic control systems that have greater sensitivity and scanning speed. defective zones with the possibility of constructing a qualitative image of the defective zone for further assessment of the performance of the entire structure with PCM.

Structure forming and managing of properties of phosphorous cast irons for parts of internal combustion engine

Purpose. Improving the mechanical and operational properties of details of internal combustion engines by managing the structure formation of phosphorous cast irons.
 Research methods. Graphitized and bleached phosphorous cast irons with lamellar and globular graphite of laboratory and industrial melts, melted in electric induction furnaces with alloying modification and fractional casting into dry sand molds were investigated. Chemical composition, microstructure, physical and mechanical properties were determined using standard methods. Non-destructive quality control of engine parts, statistical analysis of experimental data and deterministic factor analysis of the influence of structural components on the properties of the cast irons were carried out according to the methods developed with the participation of the authors. Bench and road motor tests of optimal composition cast irons details were carried out in engines according to standard and factory methods in accordance with state standards.
 Obtained results. The general laws and principles of the formation of the microstructure of cast irons with lamellar and nodular graphite are determined depending on the degree of their alloying with phosphorus and the influence of the scale factor. It has been established that phosphide eutectic in an amount of up to 5.8 % is a strengthening structural component and increases strength, hardness, wear resistance, heat resistance, and machin-ability of phosphorous cast irons with blade tools. The negative effect of phosphide eutectic on plastic properties and cyclic fracture toughness is less significant than the effect of increasing amounts of ferrite, its grain size and graphite. Optimal chemical compositions and microstructures of phosphorous cast irons for internal combustion engines details are recommended.
 Scientific novelty. For the first time, a comprehensive system for managing the properties of phosphorous cast irons has been developed, including the analytical determination of the required characteristics of structural components and the technology for their production.
 Practical value. Methods and technologies for melting, alloying, modifying, heat treatment and surface hardening of phosphorous cast irons have been developed. They make it possible to provide the required level of mechanical and operational properties of internal combustion engines details.

Application of non-destructive methods of control within the inspection of concrete structures

This paper discusses the main non-destructive quality control methods that are used in the inspection of both under construction and already existing concrete structures. Purpose of the work: to conduct a comparative analysis of non-destructive testing methods, to consider a practical example of their application in the survey of a building being reconstructed, to identify the essential points of the organization of non-destructive quality control, which must be taken into account when developing a site work execution program. Materials and methods: the application of methods of non-destructive testing, separation with spalling and the ultrasonic method of surface sounding, is considered in detail. Results: the results of the inspection of structures by the methods separation with spalling and the ultrasonic method of surface sounding are presented, the test conditions, basic requirements for correct data interpretation, and the necessary calculations are given. Recommendations are given for planning the quality control of concrete structures at the stage of organizational and technological preparation of construction. Conclusions: non-destructive quality control finds its application both in the construction of new facilities and in the inspection of existing buildings. The choice of the survey method is made at the stage of development of a site work execution program, while it is necessary to take into account the features and scope of application of a particular method, probable measurement error, it is also possible to use several methods in combination.

Non-destructive inspection and analysis of hardened steel plates by ultrasonic test with backscatter technique

In this paper, we use the ultrasonic backscatter technique for measurement of the thickness of the hardened layer (case depth) on inductions-hardened VCN 100 steel plates. The experiment includes an immersion ultrasonic test where both the sample and the ultrasonic probe are immersed in a water tank. The measurement technique is based on the backscattering of ultrasonic waves from the transition zone which lies between the hardened layer and the soft inner core. The backscattered ultrasonic signals are measured and processed by a number of signal processing schemes to extract the thickness of the hardened layer. A scanning system measures the case depth on the surface of the plate samples and produces C-scan images showing the profile of the hardened layer. This technique could be used for nondestructive testing and quality control of hardened specimens.

State primary standard of optical density unit GET 206-2016

The description of the State Primary Standard of optical density unit GET 206-2016 is given. The principle of operation of the standard, based on filtering the luminous flux of transmitted and reflected light, is described. The composition of the standard and its metrological characteristics are presented. Data on the study of the geometric and spectral characteristics of the standard are presented. Currently, GET 206-2016 allows solving the problems of metrological support of optical transmittance density measuring instruments (radiographic non-destructive quality control of materials in various industries) and optical reflection density measuring instruments (printing, applications of energy-saving and graphic technologies).

Аналіз якості структуроутворення виливків корпусних деталей з сірого чавуну

The purpose of this article is to carry out a statistical analysis quality of structure formation of castings of body parts made of gray cast iron. The magnetic method of non-destructive quality control of the coercive force was used as a criterion for the analysis of the quality under production conditions was carried out. The evaluation was carried out on two types of parts: transfer case housings and gear change housings made of SCH15, SCH18 and SCH20 cast irons, respectively. Both types of parts have similar wall thickness. The observed phenomenon is associated with deviations in the method of injection the modifier (silicomanganese) and its uneven assimilation throughout the mass of the metal. Thus, according to local X-ray spectral analysis, the distribution concentration of these elements is especially inhomogeneous in castings with a higher level of coercive force (0,07...2.09% Si and 0,04...2.15% Mn). The shape of the inclusions is the same for different Hc. Despite the close concentration in the distribution of the main components over the cross-section of the castings, we found that the reason for the difference between multiple readings obtained when measuring the coercive force is an increased proportion of graphite inclusions, oxides and sulfides. The use of such a non-destructive control method will make it possible to identify zones in products with deviations in structure and to more thoroughly analyze the possibility of defect formation (pore and crack formation).

Development software for the non-destructive control of monolithic structures in housing construction

We describe in this article the developed software package. This software package improves the efficiency of the non-destructive quality control system for monolithic structures. The need to create a comprehensive tool was justified. This tool is capable of solving complex problems, both at the stage of technological design and during construction production. In construction, atypical heterogeneous tasks often arise that must be solved in conditions of financial, labor and time constraints. This is due to the specifics of the construction industry. A new direction - “the potential for the effectiveness of organizational and technological solutions” can solve this problem. Earlier studies of the potential for using non-destructive testing methods made it possible to form a scientific base for the formation of a comprehensive program program. The methodology for calculating the potential for using non-destructive testing methods in organizing the construction of residential buildings has been described. An algorithm for determining the qualitative characteristics of the potential during the implementation of the construction project was also developed. This algorithm includes 4 stages: comparative analysis of the existing situation at the facility; selection and establishment of levels of values of the parameters of ATM calculation of organizational and technical potential; calculation of a psychophysical assessment corresponding to the value of the potential.

Использование лазерного сканирования для неразрушающего контроля качества деталей, изготовленных по технологии 3D печати

The article identifies promising areas of application of additive technologies in the production of parts and elements of aviation equipment (AT), the main tasks that need to be solved when implementing them (during the implementation process). The features of the application of laser scanning for non-destructive quality control of aircraft parts manufactured using modern additive technologies are considered. The possibility of controlling deviations in the shape and size of parts of aircraft manufactured using 3D printing technology from their 3D models by stationary and portable scanners (for example, an adapter for the air conditioning and ventilation system of an aircraft) is shown.(is represented) The article presents the main operations of the technological process of laser scanning using modern technical and software tools, the process of laser scanning of the AT part using the FARO Arm mobile CMM is implemented.

Radiographic Visibility Limit of Pores in Metal Powder for Additive Manufacturing

The quality of additively manufactured (AM) parts is determined by the applied process parameters used and the properties of the feedstock powder. The influence of inner gas pores in feedstock particles on the final AM product is a phenomenon which is difficult to investigate since very few non-destructive measurement techniques are accurate enough to resolve the micropores. 3D X-ray computed tomography (XCT) is increasingly applied during the process chain of AM parts as a non-destructive monitoring and quality control tool and it is able to detect most of the pores. However, XCT is time-consuming and limited to small amounts of feedstock powder, typically a few milligrams. The aim of the presented approach is to investigate digital radiography of AM feedstock particles as a simple and fast quality check with high throughput. 2D digital radiographs were simulated in order to predict the visibility of pores inside metallic particles for different pore and particle diameters. An experimental validation was performed. It was demonstrated numerically and experimentally that typical gas pores above a certain size (here: 3 to 4.4 µm for the selected X-ray setup), which could be found in metallic microparticles, were reliably detected by digital radiography.

Parameters of Acoustic Inhomogeneity for Nondestroductive Estimation of the Influence of Manufacturing Technology and Operational Damage on the Structure of Metal

An acoustic method for nondestructive evaluation of variations in the metal structure caused by violations in manufacturing technology or by accumulation of damage during operation has been proposed. The method is based on measuring microstructure-sensitive acoustic parameters, which are determined as normalized deviations of the ratios of the velocities of longitudinal and shear waves from the values characteristic of the “basic state” of the metal structure. Depending on the specific task, for the “basic” one we take the state of metal structure before the start of operation of the test object or the structure of metal in test samples whose strength characteristics are determined by the standard methods of destructive testing and are within acceptable limits. The relationship between the proposed acoustic parameters and the difference between the “basic” and real states of the material (in terms of the integral values of the compliance of microstructural inhomogeneities with respect to shear and longitudinal stresses) is discussed. The effectiveness of the proposed approach to assessing the structure of metal is demonstrated using the results of experimental studies of two essentially different types of structure—with isotropic and anisotropic inhomogeneities. Instrumental verification of the proposed parameters can be used for (1) nondestructive quality control of technological processes in the production of metallurgy and mechanical engineering products; (2) assessment of the degree of in-service metal damage accumulation; and (3) evaluation of mechanical properties, crack resistance characteristics, and other physical properties of metal.

Параметры акустической неоднородности для неразрушающей оценки влияния технологии изготовления и эксплуатационной поврежденности на структуру металла

In this paper, we propose a non-destructive acoustic method for assessing microstructural alterations produced in metals as a result of processing and exploitation damage. The method is based on measuring ratios of longitudinal and shear ultrasound waves velocities with subsequent normalization of these ratios to their counterparts corresponding to a “baseline state” of the metal. The choice of the baseline state depends of the particular problem and corresponds to either the pre-exploitation metal state for the object to be monitored, or the state of reference samples, for which the strength characteristics fall into acceptable range according to the results of conventional strength-evaluation methods. For the introduced Microstructure-Sensitive Acoustic parameters (MSA-parameters) characterizing alterations in the metal microstructure, we discuss the reasons of the difference between the baseline and current states of the metal in terms of the total values of the normal and tangential compliances imparted to the metal due to the appearance of microstructural heterogeneities. The efficiency of utilization of the proposed acoustic diagnostic parameters is demonstrated using experimental data for two types of metal samples with essentially different microstructure (isotropic and anisotropic heterogeneity). Measurements of the proposed microstructure-sensitive acoustic parameters can be used in a variety of applications: (i) non-destructive quality control of manufacturing technologies in metallurgy and mechanical engineering (ii) evaluation of damage accumulation during exploitation manufactured constructions/samples; (iii) evaluation of mechanical properties, fracture resistance and other physical parameters of metals.

A lightweight solution of industrial computed tomography with convolutional neural network

As an advanced non-destructive testing and quality control technique, industrial computed tomography (ICT) has found many applications in smart manufacturing. The existing ICT devices are usually bulky and involve mass data processing and transmission. It results in a low efficiency and cannot keep pace with smart manufacturing. In this paper, with the support from Internet of things (IoT) and convolutional neural network (CNN), we proposed a lightweight solution of ICT devices for smart manufacturing. It consists of efforts from two aspects: distributed hardware allocation and data reduction. At the first aspect, ICT devices are separated into four functional units: data acquisition, cloud storage, computing center and control terminals. They are distributed and interconnected by IoT. Only the data acquisition unit still remains in the production lines. This distribution not only slims the ICT device, but also permits the share of the same functional units. At the second aspect, in the data acquisition unit, sparse sampling strategy is adopted to reduce the raw data and singular value decomposition (SVD) is used to compress these data. They are then transmitted to the cloud storage. At the computing center, an ICT image reconstruction algorithm and a CNN are applied to these compressed sparse sampling data to obtain high quality CT images. The experiments with practical ICT data have been executed to demonstrate the validity of the proposed solution. The results indicate that this solution can achieve a drastic data reduction, a storage space save and an efficiency improvement without significant image degradation. The presented work has been helpful to push the applications of ICT in smart manufacturing.

DENSE 3D OBJECT RECONSTRUCTION USING STRUCTURED-LIGHT SCANNER AND DEEP LEARNING

Abstract. Structured light scanners are intensively exploited in various applications such as non-destructive quality control at an assembly line, optical metrology, and cultural heritage documentation. While more than 20 companies develop commercially available structured light scanners, structured light technology accuracy has limitations for fast systems. Model surface discrepancies often present if the texture of the object has severe changes in brightness or reflective properties of its texture. The primary source of such discrepancies is errors in the stereo matching caused by complex surface texture. These errors result in ridge-like structures on the surface of the reconstructed 3D model. This paper is focused on the development of a deep neural network LineMatchGAN for error reduction in 3D models produced by a structured light scanner. We use the pix2pix model as a starting point for our research. The aim of our LineMatchGAN is a refinement of the rough optical flow A and generation of an error-free optical flow B̂. We collected a dataset (which we term ZebraScan) consisting of 500 samples to train our LineMatchGAN model. Each sample includes image sequences (Sl, Sr), ground-truth optical flow B and a ground-truth 3D model. We evaluate our LineMatchGAN on a test split of our ZebraScan dataset that includes 50 samples. The evaluation proves that our LineMatchGAN improves the stereo matching accuracy (optical flow end point error, EPE) from 0.05 pixels to 0.01 pixels.

Non-uniformity Correction Algorithm for THz Array Detectors in High-Resolution Imaging Applications

One of the major challenges in THz imaging using array detectors is the responsivity non-uniformities across different pixels. This is caused by different pixels responding differently and non-linearly to the same incident field. Unfortunately, such responsivity non-uniformities cannot be corrected by the traditional amplitude normalization method, which only accounts for linear responsivity. Therefore, we propose a pixel calibration scheme that corrects a non-linear responsivity of individual pixels. This calibration scheme is particularly useful in a multi-frame sub-pixel imaging technique, which assumes that all pixels have the same characteristics. Using this imaging technique would allow us to achieve an image pixel size smaller than a detector pixel size, in much faster acquisition time compared with most existing systems employing a single-pixel detector. We demonstrate the performance of our pixel calibration approach through THz imaging of various objects by the multi-frame sub-pixel imaging technique. For a square aluminum piece as a test sample, total variation (TV) in the THz image is reduced by at least 12% after applying the pixel calibration. Finally, we present example uses of our proposed technique in moisture distribution imaging. The proposed technique holds promises towards rapid THz high-resolution imaging in non-destructive testing (NDT) and quality control (QC) applications.