Damage tolerant functionally graded WC–Co/Stainless Steel HVOF coatings

2010 ◽  
Vol 205 (7) ◽  
pp. 2197-2208 ◽  
Author(s):  
Alfredo Valarezo ◽  
Giovanni Bolelli ◽  
Wanhuk B. Choi ◽  
Sanjay Sampath ◽  
Valeria Cannillo ◽  
...  
Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1923
Author(s):  
Bruna Horta Bastos Kuffner ◽  
Patricia Capellato ◽  
Larissa Mayra Silva Ribeiro ◽  
Daniela Sachs ◽  
Gilbert Silva

Metallic biomaterials are widely used for implants and dental and orthopedic applications due to their good mechanical properties. Among all these materials, 316L stainless steel has gained special attention, because of its good characteristics as an implantable biomaterial. However, the Young’s modulus of this metal is much higher than that of human bone (~193 GPa compared to 5–30 GPa). Thus, a stress shielding effect can occur, leading the implant to fail. In addition, due to this difference, the bond between implant and surrounding tissue is weak. Already, calcium phosphate ceramics, such as beta-tricalcium phosphate, have shown excellent osteoconductive and osteoinductive properties. However, they present low mechanical strength. For this reason, this study aimed to combine 316L stainless steel with the beta-tricalcium phosphate ceramic (β-TCP), with the objective of improving the steel’s biological performance and the ceramic’s mechanical strength. The 316L stainless steel/β-TCP biocomposites were produced using powder metallurgy and functionally graded materials (FGMs) techniques. Initially, β-TCP was obtained by solid-state reaction using powders of calcium carbonate and calcium phosphate. The forerunner materials were analyzed microstructurally. Pure 316L stainless steel and β-TCP were individually submitted to temperature tests (1000 and 1100 °C) to determine the best condition. Blended compositions used to obtain the FGMs were defined as 20% to 20%. They were homogenized in a high-energy ball mill, uniaxially pressed, sintered and analyzed microstructurally and mechanically. The results indicated that 1100 °C/2 h was the best sintering condition, for both 316L stainless steel and β-TCP. For all individual compositions and the FGM composite, the parameters used for pressing and sintering were appropriate to produce samples with good microstructural and mechanical properties. Wettability and hemocompatibility were also achieved efficiently, with no presence of contaminants. All results indicated that the production of 316L stainless steel/β-TCP FGMs through PM is viable for dental and orthopedic purposes.


2013 ◽  
Vol 61 (1) ◽  
pp. 193-204 ◽  
Author(s):  
P.C. Wo ◽  
X.L. Zhao ◽  
P.R. Munroe ◽  
Z.F. Zhou ◽  
K.Y. Li ◽  
...  

2014 ◽  
Vol 217-218 ◽  
pp. 195-200
Author(s):  
Ren Bo Song ◽  
Ya Ping Li ◽  
Yong Jin Wang ◽  
Cui Qing Zhao

Semi-solid billet of 9Cr18 martensitic stainless steel with globular grains was made by a wavelike sloping plate experimental device, and hot compression tests were carried out in the semi-solid state of 9Cr18 semi-solid billet on Gleeble-1500 thermal simulation testing machine at the temperatures of 1250°C ~1300°C and the strain rates of 0.1 s-1~5.0 s-1to investigate the effects of thixoforming parameters on its deformation characteristics and mechanism. According to the true stress-strain curves obtained from the test, the influence of deformation temperature and strain rate on 9Cr18 semi-solid billet deformation resistance was investigated, and the deformation resistance model of specimen with coexistence of solid and liquid phases was established. In this paper, it was found that deformation mechanism changed because of different deformation temperature and strain rate. Dynamic recrystallization occured at 1250°C in different phases separately. So that big fine recrystallized grains were achieved at the soft primary austenite region while small recrystallized grains were achieved at the hard solidified liquid region. The melted metal would be extruded from the centre of the specimen to the free surface completely when the temperature was higher than 1275°C. And then specimen became FGM (functionally graded materials), with phases and properties graded distribution perpendicular to the stress direction. When thixoforming temperature reached 1300 °C, martensitic transformation occurred after rapid cooling. The mathematics models of the relation between stress and temperatures, fraction of solid, deformation rates and deformation degree of 9Cr18 semi-solid billet were regressed and established based on the dates attained from the compression deformation experiments. The R value was 0.991, and the RMSE value was 3.57.


Author(s):  
Xinglong Tan ◽  
Shaoyu Qiu ◽  
Wenyan He ◽  
Daifu Lei

The properties of nano WC/Co hardmetals prepared by different Spark Plasma Sintering processes were measured. A 4-layer Functionally Graded Materials (FGM) was also obtained by Spark Plasma Sintering technology (SPS), starting from powders of nano WC/10%Co, nano WC/12%Co, micro WC/15%Co and stainless steel disk. The other 3-layer FGM was made from powders of nano 21%Al2O3/ZrO2, nickel and stainless steel. The SPS processing led to FGM free of internal stress, which was measured using Vickers indentations.


2018 ◽  
Vol 90 (10) ◽  
Author(s):  
Mirosław Szala ◽  
Mariusz Walczak

The aim of the work was to investigate the resistance to cavitation erosion and sliding wear of sprayed HVOF coatings. M(Ni,Co)CrAlY and Cr3C2-NiCr based coatings were deposited using HVOF method onto stainless steel substrate grade AISI 304. As-sprayed coatings’ surface morphology was examined by SEM-EDS and profilometer methods. Cavitationerosion tests were conducted in distilled water with the use of vibratory rig and stationary specimen method. Cavitation erosion curves were plotted as well as cavitational wear mechanism was observed with the use of SEM microscope. Sliding wear tests were performed using the ball-on-disc tribotester with counter-specimen (ball) made of steel 100Cr6. Wearrates and coefficient of friction were computed. Normalized wear resistance with referenceto stainless steel reference sample AISI 304 was calculated. In addition, comparable analysis of wear resistance results was conducted. M(Ni,Co)CrAlY coating presented the highest cavitation erosion resistance, therefore Cr3C2-NiCr coating represented the highest sliding wear resistance of all tested materials.


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