Fatigue behavior and modeling of additively manufactured IN718: The effect of surface treatments and surface measurement techniques

Author(s):  
Seungjong Lee ◽  
Shuai Shao ◽  
Douglas N. Wells ◽  
Miroslav Zetek ◽  
Miloslav Kepka ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amr M. Elnaghy ◽  
Ayman Mandorah ◽  
Ali H. Hassan ◽  
Alaa Elshazli ◽  
Shaymaa Elsaka

Abstract Background To evaluate the effect of surface treatments on the push-out bond strength of Biodentine (BD) and white mineral trioxide aggregate (WMTA) to fiber posts. Methods Two brands of fiber posts were used: Reblida post; RP and RelyX post; RX. Each type of post (n = 80/group) was divided into four groups (n = 20/group) and exposed to surface treatment as follows: Control (no treatment), sandblasting (SB), hydrofluoric acid (HF), and TiF4 4 wt/v%. Each group was further subdivided into two subgroups (n = 10/subgroup) based on the type of CSCs used as follows: Subgroup A: BD and Subgroup B: WMTA. Push-out bond strength of BD and WMTA to glass fiber posts was assessed. Data were statistically analyzed using three-way ANOVA and Tukey’s test. A Weibull analysis was performed on the push-out bond strength data. Results BD showed higher bond strength than WMTA (P < 0.001). The push-out bond strength for posts treated with TiF4 4 wt/v% showed greater bond strength than the other surface treatments (P < 0.05). The BD/RP-TiF4 4 wt/v% showed the greater characteristic bond strength (σ0) (15.93) compared with the other groups. Surface treatments modified the surface topography of glass fiber posts. Conclusions The BD/RP-TiF4 4 wt/v% showed greater bond strength compared with the other groups. The TiF4 4 wt/v% surface treatment enhanced the bond strength of BD and WMTA to glass fiber posts than the other treatments. Surface treatment of fiber post with TiF4 4 wt/v% could be used to improve the bond strength with calcium silicate-based cements.


2016 ◽  
Vol 116 (5) ◽  
pp. 797-802 ◽  
Author(s):  
Nuno Guilherme ◽  
Chandur Wadhwani ◽  
Cheng Zheng ◽  
Kwok-Hung Chung

2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.


2004 ◽  
Vol 12 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Carlos José Soares ◽  
Marcelo Giannini ◽  
Marcelo Tavares de Oliveira ◽  
Luis Alexandre Maffei Sartini Paulillo ◽  
Luis Roberto Marcondes Martins

The purpose of this study was to evaluate the influence of different surface treatments on composite resin on the microtensile bond strength to a luting resin cement. Two laboratory composites for indirect restorations, Solidex and Targis, and a conventional composite, Filtek Z250, were tested. Forty-eight composite resin blocks (5.0 x 5.0 x 5.0mm) were incrementally manufactured, which were randomly divided into six groups, according to the surface treatments: 1- control, 600-grit SiC paper (C); 2- silane priming (SI); 3- sandblasting with 50 mm Al2O3 for 10s (SA); 4- etching with 10% hydrofluoric acid for 60 s (HF); 5- HF + SI; 6 - SA + SI. Composite blocks submitted to similar surface treatments were bonded together with the resin adhesive Single Bond and Rely X luting composite. A 500-g load was applied for 5 minutes and the samples were light-cured for 40s. The bonded blocks were serially sectioned into 3 slabs with 0.9mm of thickness perpendicularly to the bonded interface (n = 12). Slabs were trimmed to a dumbbell shape and tested in tension at 0.5mm/min. For all composites tested, the application of a silane primer after sandblasting provided the highest bond strength means.


2019 ◽  
Vol 162 ◽  
pp. 331-344 ◽  
Author(s):  
Dimitrios Mamalis ◽  
Winifred Obande ◽  
Vasileios Koutsos ◽  
Jane R. Blackford ◽  
Conchúr M. Ó Brádaigh ◽  
...  

Author(s):  
Chandramoulee Krishnamoorthy ◽  
Rahul P. Rao ◽  
Afshin J. Ghajar

This review paper specifically concentrates on heat transfer in micro-tubes and eleven experiments (on liquid flow) and two experiments (on gaseous flow) from 1991 to 2007 are reviewed critically with respect to measurement techniques, instrumentation; and factors like surface roughness and diameter that may play an important role at these small scales. Moreover, a comprehensive list of numerical and analytical results (for both liquid and gaseous flows) is presented in this paper. Interestingly, the effect of surface roughness on heat transfer does not seem to have been investigated thoroughly, as it has been observed to play a key role in influencing heat transfer at small diameters. The state-of-art review thus provides the contemporary experimenters in the field of mini-micro channel heat transfer, this tabulated data that can be used to understand how the different parameters affect the heat transfer in these small scales and a data-bank to validate future numerical and experimental work. The present study identifies the various factors that have contributed in the disparity of results found in the literature and finds that there is a need to investigate certain issues like the effects of roughness, diameter, and secondary flow due to buoyancy on heat transfer and transition. Moreover, it was observed that the start and end of the transition region at these small diameters are not validated by the any of the existing macro-scale correlations.


2012 ◽  
Vol 75 (9) ◽  
pp. 1206-1212 ◽  
Author(s):  
Raquel Castillo-Oyagüe ◽  
Raquel Osorio ◽  
Estrella Osorio ◽  
Fátima Sánchez-aguilera ◽  
Manuel Toledano

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