Cong Sun

• phD
• Shenyang at Northeastern University

40Cr steel is one of the most widely used steels in machinery manufacturing. After tempering treatment, it has good mechanical properties and low-temperature impact toughness. In order to effectively improve the machining quality and surface integrity of the parts, a new machining technology, pre-stressed dry grinding, is proposed. The technology c...

The solidification process of laser directed energy deposition (LDED) affects elemental separation, microstructure, and tensile properties. This work proposes an interval pulsed laser deposition (IPLD) process to improve the cooling rate. The IPLD and continuous laser deposition (CLD) samples are prepared at the same laser power for comparative ana...

Silicon nitride (Si3N4) is widely used in multiple fields due to excellent properties. However, the improvement of the mechanical properties by the existing processing is limited, and the surface modification mechanism of the material is not enough. Therefore, laser-assisted grinding (LAG), combing laser heating with grinding, is proposed. The LAG...

Aluminium nitride (AlN) materials are widely used in heat-dissipation substrates and electronic device packages. However, the application of aluminium nitride ceramics is hindered by the obvious anisotropy and high brittleness of its crystals, leading to poor material surface integrity and high grinding force. With the rapid development of microele...

Grinding is a generally utilized method, removing excess materials through effective abrasives. The grinding abrasives with multiple shape-position characteristics play a dominant role in determining the thermo-mechanical coupling, which may influence the surface quality directly. To investigate this correlated influence mechanism, this paper focus...

Cylindrical grinding is commonly used as the final process of machining, but its quality and efficiency are often limited by chatter phenomenon. Many research show that the result from conventional chatter analysis by using the deterministic parameters is not consistent with the practical working condition and the chatter reliability prediction in...

The grain refinement behaviors of stainless steel materials subjecting to pre-stress grinding (PG) were investigated using a 3D FE-CA coupling method in conjunction with experimental comparisons. The qualitative agreement with experimental results was found to be good. The visual tracking of the evolution of recrystallized grains (R-grains) during...

In modern manufacturing industry, surface heat treatment is usually required after grinding because strengthening surfaces is in extensive demand. However, most existing strengthening methods have limitations in manufacturing cost and efficiency, and previous studies mainly focus on improvement by heat treatment. Therefore, the pre-stressed dry gri...

The mechanical properties of direct laser deposition (DLD) parts are crucial for engineering applications, which are determined by the microstructure and texture. To achieve fine microstructure and higher mechanical performance, pulsed laser deposition is used to generate less heat accumulation and a higher cooling rate. However, the relationship b...

In order to improve the surface integrity and enhance stress corrosion crack (SCC) resistance of stainless steel (SS) materials, this study investigates the application of pre-stress grinding (PG) technique. The impact of PG on various surface integrity parameters, including residual stress, surface topography, surface roughness, and microstructure...

Purpose This paper aims to study the influence of the different parameters of magnetorheological polishing fluids (MRP fluids) on the surface roughness and material removal rate (MRR) of the workpiece surface in the reciprocating magnetorheological polishing (RMRP) process. Design/methodology/approach A series of single-factor experiments are perf...

In order to investigate the effect of pre-stress grinding on SCC resistance and its mechanism, a series of experiments and simulations were conducted. In the beginning, the SCC behaviors of 304 stainless steel on machined surface were studied. Then the SCC-relevant parameters of the ground surface were characterized in terms of residual stress and...

Purpose This paper aims to study the effects of the processing parameters in the reciprocating magnetorheological polishing (RMRP) on abrasive particle trajectory by the simulation analysis, which provides a basis for the machining uniformity of the workpiece. Design/methodology/approach The principle of the RMRP method is discussed, and a series...

Ti–6Al–4V alloys fabricated by inside-beam powder feeding (IBPF) generally exhibit coarse columnar α-lath resulting in slightly poorer mechanical properties than forged parts. In this study, a laser remelting strategy with an annular beam was used to improve the microstructure and refine grain size, thus improving the mechanical properties of IBPF...

Aiming to improve the dynamic and static contact performance of 40Cr alloy parts, a grind-strengthening (GS) compound process is applied to the finish machining and surface quenching heat treatment of 40Cr alloy steel, which makes the material undergo a modification behavior of dynamic phase transformation introduced by high grinding heat and sever...

Aiming to explore the corrosion mechanisms on the ground surface in pre-stress grinding and pursue grinding parameters that could help obtain the machined surface with higher corrosion resistance, in the present study, a series of experiments and simulations are conducted. Firstly, the ground surfaces operated by pre-stress grinding are corroded in...

Effectively measuring and predicting the grinding temperature is significant for accurately controlling machined surface quality. However, the spatial limitations of the contact area and the time-varying of heat sources make the accurate acquisition of grinding temperature challenging. Existing methods have made critical achievements, but further e...

The grinding surface mechanical property is important for its working life span, which is determined by the microstructure distribution. To improve the machining mechanical performance, the greenly grinding generated heat is utilized to generate the coating layer without extra liquid. However, the coating layer microstructure composite is difficult...

Purpose This paper aims to analyze the significance of machining parameters (workpiece’s rotational speed, magnet coil current and working gap) on final Ra (surface roughness) and material removal rate (MRR) of workpiece in reciprocating magnetorheological polishing (RMRP) process. Design/methodology/approach The research is planned to analyze, mo...

As an energy-saving and eco-friendly combined machining, Grinding-strengthening (GS) technology has been widely applied. Because the strengthened layer is a critical factor affecting surface mechanical properties, it is worthwhile to study the predicting method of surface-strengthened layer. The relevance of strengthened layer and dynamic vibration...

Grind-strengthening represents a novel surface modification process that combines a precision removal process of material and the strengthening function of surface modification. The high heat and severe plastic deformation (SPD) of the ground superficial layer can induce the phase transformation and dynamic recrystallization (DRX) grain refinement...

Direct laser deposition (DLD) is widely used in precision manufacturing, but the process parameters (e.g., laser power, scanning patterns) easily lead to changes in dimensional accuracy and structural properties. Many methods have been proposed to analyze the principle of distortion and residual stress generation, but it is difficult to evaluate th...

Comprehension of the tribological behavior of magnetorheological fluid (MRF) is crucial in many fields, particularly those related to seal wear. The sealing conditions are more complex than traditional media due to composition and rheological characteristics of MRF. The sealing pairs are prone to wear failure when in contact with magnetic particles...

In the abrasive grinding hardening (AGH) of metal materials, the microstructure of the surface changes under the action of the intense grinding heat and forms the evolution layer covering the grinding surface with unique mechanical properties. The effective control of microstructure in the layer has great practical significance for obtaining high-p...

As the main factor of magnetorheological polishing (MRP), the magnetorheological polishing fluids (MRP fluids) directly affect the machining results of the workpiece surface. In this study, the preparation and performance test of MRP fluids are carried out. It is to evaluate the polishing effects of the workpiece by experimental design of the prepa...

The rolling contact fatigue is commonly seen in industrial applications. Studies mainly focus on fatigue evolution caused by heat treatment. However, the combined machining includes thermal-mechanical coupling and transformation. The generated residual stress can be another factor to decide contact fatigue. A sequent study is conducted to investiga...

Purpose This paper aims to study the effects of the different processing parameters in the reciprocating magnetorheological polishing (RMRP) on the surface roughness (Ra) and material removal rate (MRR) of the workpiece surface. Design/methodology/approach The principle of RMRP method is discussed, and a series of the single factor experiments are...

In double-sided grinding, the material removal on the surface of the workpiece is non-uniform. The thermal deformation of the material may be one of the influencing factors. However, it is difficult to predict and measure the temperature field distribution in the workpiece in double-sided grinding. In this paper, based on the grain trajectory model...

Different from the general grinding process, the disc grinding quality varies with the part position due to the complicated abrasive removal. Based on the main shaft system dynamic-static characteristic, the work aims to study the disc grinding surface generation mechanism. The element deformation model on dynamic-static characteristic is establish...

Disc grinding is a commonly-utilized removal technology to generate the machining surface with higher precision. The material removal is caused by the force interaction between abrasives, which releases much heat during grinding. The dynamic thermal–mechanical coupling can be a crucial factor to influence the surface performance of the workpiece. H...

We are organizing a Special Issue "Advanced Mathematical Methods and Engineering Applications for High-Speed Grinding Technology" in Mathematical Problems in Engineering (ISSN 1563-5147, IF 1.305, Indexed by SCIE, Ei Compendex, Scopus). The purpose of this Special Issue is to bring together original research articles and review articles in the fiel...

The abrasive grinding hardening is not only a high precision material removal process, but also generates metamorphic layers to improve surface strength, which is affected by surface material grain size. As the grain size is decided by dynamic recrystallization phenomenon under grinding thermal-stain coupling, the grain refinement mechanism should...

The grinding residual stress plays a major role in deciding the workpiece’s surface quality, including the corrosion resistance, the fatigue property, and the reliability. Moreover, formation process of grinding residual stress accompanies with dynamic material’s removal action, which results in undulation of the mechanical parameters. The distribu...

In this study, a new reciprocating magnetorheological polishing (RMRP) method for a flat workpiece was proposed. Based on the RMRP principle and Preston equation, the material removal rate (MRR) model of the RMRP as well as its normal polishing pressure model was established. On this basis, the effects of different technological parameters includin...

The prediction of grinding force has great significance in improving grinding quality and efficiency. This paper presents a predictive force model in plunge facing grinding considering both the cutting mechanism of single grain and the random nature of wheel topography. The model includes cutting deformation force and frictional force, which mainly...

Disc grinding is a commonly-utilized removal technology to generate the machining surface with higher precision. The material removal is caused by the force interaction between abrasives, which releases much heat during grinding. The dynamic thermal-mechanical coupling can be a crucial factor to influence the surface performance of the workpiece. H...

This study aims to investigate the metallurgical behavior of high strength alloy steel 40Cr during the grinding strengthening (GS) process. The grinding heat can cause phase transformation, which increases surface hardness during the GS process. It is worthwhile mentioning that the severe plastic deformation can easily lead to dynamic recrystalliza...

Double side grinding is a process with high processing efficiency in which the wheel and the workpiece are in surface contact. But the phenomenon that the workpiece surface profile is out of tolerance exists because of the material removal non-uniformity in the grinding process. In order to improve the surface integrity of the ground workpiece, the...

A deleterious Laves phase forms in the solidified structure of Inconel 718 (IN718) alloy during laser cladding. However, effective removal methods have not yet been identified. In this study, we first added the IN718 alloy cladding layers with a trace amount of vanadium (V, 0.066 wt.%). Then, we studied the solidification structure of cladding laye...

Grinding hardening is a kind of attractive processing technology, which utilizes grinding heat to generate the hardening layers. Previous studies have attached the importance on generation mechanism in experiments and simulations. However, grinding hardening is a dynamic hardness improvement process due to the system’s dynamic characteristics, whos...

The disc grinding has become a widely used technology in the precision-manufacturing process for plate stainless steel. However, embossment phenomenon occurs on the ground workpiece's surface. Moreover, the workpiece's removal rate can be applied to measure the embossment. In most studies, the researches on the disc grinding technology mainly focus...

The workpiece’s surface topography is always a key factor to measure the quality of the workpiece’s finish. However, most previous studies on modeling of the workpiece’s surface topography neglect the dynamic hardening effect, which derives from the workpiece’s material microstructure transformation. In this paper, a new coupling model is establish...

Pre-stress hardening grinding (PSHG) is a complex process that combines pre-stress grinding and grinding hardening. Pre-stress, as input stress, has been working throughout the grinding process. Since the grinding heat generates on the surface of material, unloading the pre-stress at different time nodes will affect the phase change after the grind...

The grinding hardening is an integrated manufacturing technology which combines the surface hardening theory and the grinding technology. However, the grinding chatter accompanies with the whole grinding hardening process. It is the existence of the grinding chatter that makes the transformation unsteady. To this end, the paper presents a three-hyb...

Grinding chatter is a kind of self-excited vibration which does not need external motivation. However, the internal motivation exists in the form of the grinding force. The grinding force is time-varying due to the regeneration effects between the grinding wheel and the workpiece. Generally, the chatter strength is reflected by the grinding force,...

Surface integrity is a major factor to influence the contact property of the workpiece. Grinding is the common process to accomplish the workpiece’s surface integrity in modern mechanical processing. However, grinding chatter always stems from the inside of the grinding system and can result in the low precision of the workpiece’s surface topograph...

Surface grinding is always accompanied with chatter due to self-excited vibration. It often leads to an unexpected impact on the quality of the workpiece’s topography. However, the chatter is regarded as a harmonic vibration in most topography researches. This may lose preciseness when the relative vibration and the abrasive trajectory are taken in...

Workpiece surface topography has a significant influence on workpiece performance, especially on the roughness which has been a topic of extensive research. The workpiece surface topography can be considered as the result of individual grain action. This interaction is very complex depending on various factors involving the wheel topography, the gr...

Pre-stressed hardening grinding (PSHG) which blends the principle of pre-stressed machining and grinding hardening technology is a complicated thermal-mechanical coupling process. As the main indexes of surface integrity, residual stress and surface roughness have an important effect on the functional performance of workpiece. In order to reveal th...