Solution to Inverse Problem of Manufacturing by Surface Modification With Controllable Surface Integrity Correlated to Performance: A Case Study of Thermally Sprayed Coatings for Wear Performance

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
X. P. Zhu ◽  
P. C. Du ◽  
Y. Meng ◽  
M. K. Lei ◽  
D. M. Guo
Keyword(s):  
Inverse Problem ◽  
Surface Modification ◽  
Surface Integrity ◽  
High Performance ◽  
Surface Characteristics ◽  
Spray Angle ◽  
Functional Surface ◽  
Machining Processes ◽  
Wear Performance ◽  
Surface Features

Inverse problem of manufacturing is studied under a framework of high performance manufacturing of components with functional surface layer, where controllable generation of surface integrity is emphasized due to its pivotal role determining final performance. Surface modification techniques capable of controlling surface integrity are utilized to verify such a framework of manufacturing, by which the surface integrity desired for a high performance can be more effectively achieved as reducing the material and geometry constraints of manufacturing otherwise unobtainable during conventional machining processes. Here, thermal spraying of WC–Ni coatings is employed to coat stainless steel components for water-lubricated wear applications, on which a strategy for direct problem from process to performance is implemented with surface integrity adjustable through spray angle and inert N2 shielding. Subsequently, multiple surface integrity parameters can be evaluated to identify the major ones responsible for wear performance by elucidating the wear mechanism, involving surface features (coating porosity and WC phase retention) and surface characteristics (microhardness, elastic modulus, and toughness). The surface features predominantly determine tribological behaviors of coatings in combination with the surface characteristics that are intrinsically associated with the surface features. Consequently, the spray process with improved N2 shielding is designed according to the desired surface integrity parameters for higher wear resistance. It is demonstrated that the correlations from processes to performance could be fully understood and established via controllable surface integrity, facilitating solution to inverse problem of manufacturing, i.e., realization of a material and geometry integrated manufacturing.

Correlation of Process Parameters to Surface Integrity Responsible for Wear Resistance of HVOF Sprayed WC-Ni Coatings

2017 ◽  
Author(s):  
X. P. Zhu ◽  
P. C. Du ◽  
Y. Meng ◽  
M. K. Lei ◽  
D. M. Guo
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Elastic Modulus ◽  
Process Parameters ◽  
Surface Integrity ◽  
High Performance ◽  
Surface Characteristics ◽  
Wear Performance ◽  
Final Performance

Surface integrity of high performance components has a profound influence on the final performance. Therefore, surface integrity is a key point for realizing high performance manufacturing by which manufacture processes and parameters can be pre-selected according to a required functional performance of components, i.e., solving inverse problem of manufacturing, as long as correlations could be established respectively for between processes and surface integrity, and between surface integrity and performance. However, in practice it is still difficult in correlating processes to performance through surface integrity, due to the material and geometry constraints hindering achievability of a desired surface integrity during conventional manufacturing as well as the complex influence of multiple surface integrity parameters on a final performance. In this study, thermally sprayed WC-10Ni coatings onto stainless steel using high velocity oxy-fuel (HVOF) spraying process are investigated to identify the surface integrity predominantly determining the water-lubricated wear performance of coated steel, and then to correlate it to process parameters. The controllable surface integrity facilitates identifying responsible surface integrity parameters for a required high performance, and subsequently deriving necessary process parameters for achieving the desired responsible surface integrity. Specifically, HVOF process parameters are adjusted by changing the oxygen-to-fuel (O/F) ratio to control thermal and mechanical processing loads, i.e. temperature of heated in-flight spraying powders and impact velocity of the molten splats onto stainless steel to form the coatings. Surface features including porosity and phase structure, and surface characteristics including hardness, elastic modulus, and fracture toughness were studied with respect to the wear performance. The porosity and WC phase composition of coatings are identified responsible for the wear performance, as two essential surface integrity parameters that in turn greatly affect the surface characteristics including coating hardness, elastic modulus and fracture toughness. Consequently, the process parameter O/F is feasibly correlated to wear resistance through the responsible surface integrity parameters, as elucidating the coating formation mechanism of influence of particle velocity and temperature on the coating porosity and WC decomposition.

Reducing Geometrical, Physical, and Chemical Constraints in Surface Integrity of High-Performance Stainless Steel Components by Surface Modification

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
M. K. Lei ◽  
X. P. Zhu ◽  
D. M. Guo
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Surface Integrity ◽  
High Performance ◽  
Base Material ◽  
Chemical Characteristics ◽  
Geometrical Feature ◽  
Physical And Chemical Characteristics ◽  
Surface Modified ◽  
Physical And Chemical

High-performance manufacturing is difficult to perform using conventional materials removal processes since a surface integrity demand for high-performance components is strongly restricted by intrinsic interactions between the geometrical feature of components and the physical and chemical characteristics of the base material. Surface modification techniques based on known processing loads, including mechanical, thermomechanical, and thermochemical loads, are utilized for manufacturing the Fe–Cr–Ni austenitic stainless steel components. The geometrical feature and the physical and chemical characteristics as well as the controllable interactions between them are identified in the surface integrity of the surface-modified components by creating new surface layers coupled with base material. The effective surface states control, including surface morphology, microhardness, and residual stress, leads to surface integrity improvement by reducing geometrical, physical, and chemical constraints from base materials, otherwise unobtainable merely using conventional materials removal manufacturing. The fatigue life of the surface-modified components is significantly increased due to the improved surface integrity. It is proposed that high surface integrity possesses a pivotal role between the functional properties of components and their geometrical feature and materials characteristics for the high-performance manufacturing.

Mussel-inspired surface functionalization of porous carbon nanosheets using polydopamine and Fe3+/tannic acid layers for high-performance electrochemical capacitors

2017 ◽  
Vol 5 (48) ◽  
pp. 25368-25377 ◽  
Author(s):  
Yeong A. Lee ◽  
Jiyoung Lee ◽  
Dae Wook Kim ◽  
Chung-Yul Yoo ◽  
Sang Hyun Park ◽  
...  
Keyword(s):  
Surface Modification ◽  
Tannic Acid ◽  
Surface Functionalization ◽  
Porous Carbon ◽  
High Performance ◽  
Electrochemical Capacitors ◽  
Carbon Nanosheets

The mussel-inspired surface modification for high-performance electrochemical capacitors is demonstrated.

scholarly journals Preparation of high-performance toluene adsorbents by sugarcane bagasse carbonization combined with surface modification

RSC Advances ◽  
2020 ◽  
Vol 10 (40) ◽  
pp. 23749-23758
Author(s):  
Yu Wang ◽  
Wangsheng Chen ◽  
Bo Zhao ◽  
Huaqin Wang ◽  
Linbo Qin ◽  
...  
Keyword(s):  
Surface Modification ◽  
Sugarcane Bagasse ◽  
High Performance ◽  
Activated Carbons ◽  
Excellent Performance

A series of activated carbons were prepared by carbonizing sugarcane bagasse combined with surface modification, which showed an excellent performance of adsorbing toluene (522 mg g−1 at 30 °C).

Clindamycin-loaded titanium prevents implant-related infection through blocking biofilm formation

2021 ◽  
pp. 088532822110511
Author(s):  
Youbin Li ◽  
Shaochuan Wang ◽  
Shidan Li ◽  
Jun Fei
Keyword(s):  
Surface Modification ◽  
Rat Model ◽  
Biofilm Formation ◽  
High Performance ◽  
Bacterial Colonization ◽  
Tissue Homogenate ◽  
Tartrate Resistant Acid Phosphatase ◽  
Layer By Layer

Implant-related infection is a disastrous complication. Surface modification of titanium is considered as an important strategy to prevent implant-related infection. However, there is no recognized surface modification strategy that can be applied in clinic so far. We explored a new strategy of coating. The clindamycin-loaded titanium was constructed by layer-by-layer self-assembly. The release of clindamycin from titanium was detected through high performance liquid chromatography. Different titanium was co-cultured with Staphylococcus aureus for 24 h in vitro, then the effect of different titanium on bacterial colonization and biofilm formation was determined by spread plate method and scanning electron microscopy. Cytotoxicity and cytocompatibility of clindamycin-loaded titanium on MC3T3-E1 cells were measured by CCK8. The antibacterial ability of clindamycin-loaded titanium in vivo was also evaluated using a rat model of osteomyelitis. The number of osteoclasts in bone defect was observed by tartrate-resistant acid phosphatase staining. Bacterial burden of surrounding tissues around the site of infection was calculated by tissue homogenate and colony count. Clindamycin-loaded titanium could release clindamycin slowly within 160 h. It reduced bacterial colonization by three orders of magnitude compare to control ( p < .05) and inhibits biofilm formation in vitro. Cells proliferation and adhesion were similar on three titanium surfaces ( p > .05). In vivo, clindamycin-loaded titanium improved bone healing, reduced microbial burden, and decreased the number of osteoclasts compared control titanium in the rat model of osteomyelitis. This study demonstrated that clindamycin-loaded titanium exhibited good biocompatibility, and showed antibacterial activity both in vivo and in vitro. It is promising and might have potential for clinical application.

An Inverse Algorithm to Estimate Spatially Varying Thermal Contact Resistance

2002 ◽  
Author(s):  
Eduardo Divo ◽  
Alain J. Kassab ◽  
Jennifer Gill
Keyword(s):  
Inverse Problem ◽  
Contact Resistance ◽  
Objective Function ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Random Noise ◽  
Surface Characteristics ◽  
Interfacial Region ◽  
Field Problem ◽  
Additional Information

Characterization of the thermal contact resistance is important in modeling of multi-component thermal systems which feature mechanically mated surfaces. Thermal resistance is phenomenologically quite complex and depends on many parameters including surface characteristics of the interfacial region and contact pressure. In general, the contact resistance varies as a function of pressure and is non-uniform along the interface. An inverse problem is formulated to estimate the variation of the contact resistance. A two-dimensional model is considered where the contact resistance is sought along the contact line at the interface between two regions. Temperature measured at discrete locations using embedded sensors placed in proximity to the interface provides the additional information required to solve the inverse problem. Given current estimates of the contact resistance as a function of position along the interface, a forward problem is solved, and a quadratic objective function is formulated to evaluate the difference between predicted temperatures at the sensors and those measured. A genetic algorithm is used to minimize the objective function and obtain the best estimate of the contact resistance. A boundary element method is used to solve the forward temperature field problem. Numerical simulations are carried out to demonstrate the approach. Random noise is used to simulate the effect of input uncertainties in measured temperatures at the sensors.

Sign in / Sign up

Export Citation Format

Share Document