Cold Spray Deposition of Pure Titanium Coating Onto High Strength Substrate With Ultra-High Bond Strength

Author(s):  
Davoud M. Jafarlou ◽  
Gehn Ferguson ◽  
Aaron Nardi ◽  
Victor Champagne ◽  
Ian R. Grosse

Abstract Cold spray (CS) is a relatively new spray coating technology which has opened up a new avenue for deposition of bulk coatings with a thickness in the millimeter range. The unique bonding mechanism of the CS process facilitates deposition of commercially pure titanium (CP-Ti) on a wide range of substrates including high strength alloys. In this paper we present a multi-stage bond coat deposition process using a mixture of ultra-hard ceramic beads and CP-Ti prior to the top CP-Ti coating deposition to produce a coating layer with promising bond strength. In addition, three combinations of the carrier gas temperature (450, 540, and 550 °C), and pressure (2.5 and 3.8 MPa) were considered for maximizing bond strength. The relationship between bond strength and surface roughness was also examined. The shear test results indicated a significant high bond strength of approximately 195 MPa for the gas pressure of 3.8 MPa and temperature of 450 °C owing to the newly introduced bond coat deposition method. The relatively high bond strength is explained by the beneficial effect of multi-stage bond coat prior to the deposition of the bond coat. The results also indicated a tradeoff between bond strength and obtained surface roughness.

2020 ◽  
Vol 165 ◽  
pp. 05015
Author(s):  
Ji Xiu Zhang ◽  
Ye Zhang ◽  
Ji Kang Liu ◽  
Yuan Chao Miao ◽  
Sai Hong Duan

In this paper, a new early strength tile adhesive is prepared by using α- high strength gypsum and its properties are discussed. The research methods refer to relevant Chinese standards. The results show that the tensile bond strength of the adhesive can reach 0.6 MPa in one day and 1.5 MPa in 7 days, which is close to 80% of 28-day strength. It is indicating that the adhesive has high bond strength, rapid strength development, and high dimensional stability. It effectively solves the problems that the traditional cement-based tile adhesive is prone to hollowing, falling off, and cracking. Additionally, no interface treatment is required during the using process of this gypsum-based adhesive.


Author(s):  
Karibeeran Shanmuga Sundaram ◽  
Gurusami Kiliyappan ◽  
Senthil Kumaran Selvadurai

Laser shock peening (LSP) is one of the innovative technique that produces a compressive residual stress on the surface of metallic materials, thereby significantly increasing its fatigue life in applications where failure is caused by surface-initiated cracks. The specimens were treated with laser shock waves with different processing parameters, and characterization studies were made on treated specimens. The purpose of the present study was to investigate the influence of Nd:YAG laser on commercially pure titanium (CP-Ti) used in prosthetic dental restorations. The treatment influenced change in microstructure, micro hardness, surface roughness, and wear resistance characteristics. Though CP-Ti is considered as an excellent material for dental applications due to its outstanding biocompatibility, it is not suitable when high mastication forces are applied. In the present study, pulsed Nd:YAG laser surface treatment technique was adopted to improve the wear resistance of CP-Ti. The wear test pin specimens of CP-Ti were investment cast with centrifugal titanium casting machine. The wear properties of specimens were evaluated after LSP on a “pin-on-disc” wear testing tribometer, as per ASTM G99-05 standards. The results of the wear experiment showed that the treated laser surface has higher wear resistance, micro hardness, and surface roughness compared to as-cast samples. The improvement of wear resistance may be attributed due to grain refinement imparted by LSP processes. The microstructure, wear surfaces, wear debris, and morphology of the specimen were analyzed by using optical electron microscope, scanning electron microscope, and X-ray diffraction (XRD). The data were compared using ANOVA and post-hoc Tukey tests. The characteristic change resulted in increase in wear resistance and decrease in wear rate. Hence, it is evident that the more reliable and removable partial denture metal frameworks for dental prostheses may find its applications.


Author(s):  
J. Wei ◽  
S. S. Deng ◽  
C. M. Tan

Silicon-to-silicon wafer bonding by sol-gel intermediate layer has been performed using acid-catalyzed tetraethylthosilicate-ethanol-water sol solution. High bond strength near to the fracture strength of bulk silicon is obtained at low temperature, for example 100°C. However, The bond efficiency and bond strength of this intermediate layer bonding sharply decrease when the bonding temperature increases to elevated temperature, such as 300 °C. The degradation of bond quality is found to be related to the decomposition of residual organic species at elevated bonding temperature. The bubble generation and the mechanism of the high bond strength at low temperature are exploited.


1962 ◽  
Vol 35 (4) ◽  
pp. 1060-1062
Author(s):  
A. I. Yakubchik ◽  
S. Ya Grilikhes ◽  
B. I. Tikhomirov ◽  
V. S. Purlova

Abstract The adhesive composition based on hydrogenated unbranched 1,4-polybutadiene gives a high bond strength between polyethylene and brass, and brass-plated metal, and rubber.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Rihong Cao ◽  
Wenyu Tang ◽  
Hang Lin ◽  
Xiang Fan

Binary-medium specimens were fabricated using the particle flow code, and the shear strength, dilatancy, and failure behavior of the binary-medium specimens with different bond strength ratios (0.25, 0.5, 0.75, and 1.0) under different normal stresses were studied. Numerical results show that the bond strength ratio and normal stresses considerably influence the shear strengths of binary-medium interface. Shear strength increases as the bond strength ratio and normal stress increase. The dilation of interfaces with high bond strength ratios is more evident than those of interfaces with lower bond strength ratios, and the curves for the high bond strength ratio exhibit remarkable fluctuations during the residual stage. At increased normal stress and bond strength ratio, the peak dilation angle shows decreasing and increasing trends successively. In this study, the specimens exhibited three kinds of failure modes. In mode II, the sawtooth experienced shear failure, but some tensile cracks appeared on the interface of the binary-medium. In mode III, no sawtooth was cut off, indicating tensile failure on the interface. At a low bond strength ratio, damage or failure is mostly concentrated in the upper part of the model. Failure parts gradually transfer to the lower part of the model when the bond strength ratio and normal stress increase. Furthermore, evident tensile cracks occur on the interface. When the bond strength ratio reaches 1.0, the failure mode of the specimen gradually transforms from sheared-off failure to chip-off failure. The number of microcracks in the specimens indicates that the lower the bond strength ratio, the more severe the damage on the specimens.


2011 ◽  
Vol 391-392 ◽  
pp. 807-811
Author(s):  
Fang Liu ◽  
Zhi Bin Zhang ◽  
Ling Ling Xu ◽  
Ming Shu Tang

The epoxy resin based repairing material(REM) is suitable for repairing cracks and holes in concrete or broken concrete due to its high bond strength and high durability. The compressive strength and flexile strength are 76.4MPa and >12.5MPa at 28d, and the retest strength still remain 73.4MPa and >12.5MPa respectively. The fracture location of cement mortar specimen bonded by RME is at cement mortar, that is, the bond strength between REM and cement mortar is more than mortar itself. The compressive strength of RME keeps 93.3% under ultraviolet light radiation (Peak Value 308nm, 49.5 W/m2) for 1700h.


2012 ◽  
Vol 445 ◽  
pp. 685-690 ◽  
Author(s):  
A. Binnaz Hazar Yoruc ◽  
Aysu Karakas ◽  
Oktay Elkoca ◽  
Yeliz Koca Ipek

Hydroxyapatite (HA) is the major component of the natural hard tissues such as teeth and bone. It has been studied extensively as a candidate biomaterial for its use in prosthetic applications. However, the main weakness of this material lies in its poor mechanical strength which makes it unsuitable for load-bearing applications. On the other hand zirconia (ZrO2) powder has been widely studied because of its high strength and fracture toughness and good biocompatibility. Therefore, the addition of zirconia phase into HA will improve the mechanical properties and biocompatibility of HA ceramics. The present study focused on coating of HA-ZrO2 on commercially pure titanium (cp-Ti) using novel biomimetic sol-gel method. The HA-ZrO2 coatings produced with BSG method were exhibited highly crystalline and pure structure. The coating thickness of the samples was not significantly influenced by the change in gelatin concentration and volume. It was concluded that the suggested coating method is a useful method to produce a biomimetic coating layer on the cp-Ti sample surfaces.


2012 ◽  
Vol 37 (3) ◽  
pp. 253-262 ◽  
Author(s):  
IG Haneda ◽  
RG Fonseca ◽  
FO Abi-Rached ◽  
GL Adabo ◽  
CAS Cruz

SUMMARY This study evaluated the shear bond strength (SBS) and stability of commercially pure titanium (CP Ti)/repair material interfaces promoted by different repair systems. One hundred CP Ti cast discs were divided into five repair system groups: 1) Epricord (EP); 2) Bistite II DC (BT); 3) Cojet (CJ); 4) Scotchbond Multi-Purpose Plus (SB) (control group); and 5) Cojet Sand plus Scotchbond Multi-Purpose Plus (CJSB). The specimens were stored in distilled water for 24 hours at 37°C, thermal cycled (5000 cycles, 5°-55°C) and stored under the same conditions for either 24 hours or six months (n=10). SBS was tested and the data were analyzed by two-way analysis of variance (ANOVA) and Tukey test (α=.05). Failure mode was determined with a stereomicroscope (20×). The repair system, storage time, and their interaction significantly affected the SBS (p<0.001). At 24 hours, CJSB exhibited the highest SBS value, followed by CJ. At six months, these two groups had similar mean SBS (p>0.05) and higher means in comparison to the other groups. For both storage times, BT presented the lowest SBS, while the EP and SB groups did not differ significantly from one another (p>0.05). There were no significant differences in SBS between the storage times for the groups EP and CJ (p>0.05). The groups BT, SB, and CJSB showed 100% adhesive failure, irrespective of storage time. The CJSB group showed the highest SBS at both storage times. At six months, the CJ group exhibited a similar SBS mean value when compared to the CJSB group. Water storage adversely affected the groups BT, SB (control group), and CJSB. Considering SBS values, stability, and the failure mode simultaneously, the CJ group showed the best CP Ti repair performance.


Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1352 ◽  
Author(s):  
Yi Zhang ◽  
Jieyu Zhang ◽  
Mingsong Chen ◽  
Jing Luo ◽  
Sheldon Q. Shi ◽  
...  

Soybean meal (SM)-based adhesive exhibited a great potential to replace petroleum-derived ones to alleviate the energy crisis and eliminate carcinogenic formaldehyde. However, the bad water resistance (caused by low crosslinking density) and inherent brittleness of SM adhesive severely hindered its application. However, improving crosslinking density is generally accompanied by a toughness reduction of the adhesive. Herein, we developed a flexible long-chain starch with a hyper-branched structure (HD), and incorporated it with SM and a crosslinking agent to prepare a novel SM adhesive. Results showed that this adhesive exhibited both excellent water resistance and enhanced toughness. The wet bond strength of plywood fabricated using this adhesive was 354.5% higher than that of SM adhesive. These achievements are because introducing HD with hyper-branched groups enhanced crosslinking density, while HD’s flexible long-chain structure improved toughness of the adhesive. This HD can promote the development of tough and hydrophobic bio-based composites.


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