Dual Atmosphere Isothermal Aging and Rapid Thermal Cycling of Ag-Ni and Ag-CuO Stainless Steel to Zirconia Braze Joints

2019 ◽  
Vol 166 (10) ◽  
pp. F594-F603
Author(s):  
Quan Zhou ◽  
Thomas R. Bieler ◽  
Jason D. Nicholas
Keyword(s):  
Stainless Steel ◽  
Thermal Cycling ◽  
Isothermal Aging ◽  
Rapid Thermal Cycling ◽  
Dual Atmosphere

Thermal shock resistance of Ti3SiC2 ceramic under extremely rapid thermal cycling

2021 ◽  
Vol 866 ◽  
pp. 158985
Author(s):  
Xiaojia Su ◽  
Yiwang Bao ◽  
Detian Wan ◽  
Haibin Zhang ◽  
Ludi Xu ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Shock Resistance ◽  
Rapid Thermal Cycling

Cyclone Maintenance Improvement via Special Refractory Anchor Pin Studs

2004 ◽  
Author(s):  
Stephen R. Swartz
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Thermal Cycling ◽  
Thermal Spray ◽  
Effective Means ◽  
Protective Layer ◽  
Spray Coating ◽  
Cycle Performance ◽  
Alloy 625 ◽  
430 Stainless Steel

Since the inception of the cyclone style boiler, industry has become accustomed to performing routine maintenance during every scheduled shutdown occurring 12 months to 18 months between cycles. These maintenance cycles are influenced by service factor, loading and the type design. The same problems exist in both the standard and super critical cyclones; severe deterioration of refractory and the anchoring pin studs. This paper focuses on one type of refractory failure mechanism caused by the anchoring pin studs. Most operators have found that the most effective means of applying refractory in this type situation is to “ram” the refractory in and around the anchoring pin studs thus creating a dense lining with maximum integrity. Coupled with proper application of anchoring pin studs and a special designed coating, typical volumetric expansion of the pin studs from corrosion attack and oxidation is eliminated thus extending the life of the refractory. This mechanism is discussed along with the results of the coating performance as it relates to extreme heat oxidation and thermal cycling in laboratory tests. A protective coating was developed using a nano-cored thermal spray wire technology that produces a uniform, adherent protective layer against high temperature corrosion and oxidation. The coating yields similar thermal conductivity as a bare stud thus experiencing excellent thermal cycle performance. This specially designed thermal spray coating is applied to standard 430 stainless steel pin studs thus providing the necessary barrier against aggressive high temperature environments while maintaining excellent heat conductivity. The coating has a high amount of tungsten (40+%) in a nickel matrix with greatly reduced oxides at the substrate and throughout the coating. With these attributes for the anchoring pin studs in mind, a newly designed stud was evaluated in heat oxidation tests up to 2000°F and thermal cycling test and compared to 430 stainless steel, chromized and Alloy 625. The new stud out-performed all others even in the as-welded condition. Further corrosion testing in ferric chloride (ASTM G48) showed them to be superior to Alloy 72 and Alloy 625 in the thermal spray and welded condition. Proper welding equipment and welding techniques are also discussed since weld continuity impacts overall performance of anchoring pin studs with refractory linings. A major test site will be examined in the spring of 2004 for it’s full effectiveness in service and will be documented in order that all data retrieved would be available to the entire industry.

Precipitation and impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel during isothermal aging

2014 ◽  
Vol 612 ◽  
pp. 63-70 ◽  
Author(s):  
Jian Han ◽  
Huijun Li ◽  
Frank Barbaro ◽  
Laizhu Jiang ◽  
Zhixiong Zhu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Impact Toughness ◽  
Ferritic Stainless Steel ◽  
Isothermal Aging

scholarly journals Temperature dependence of corrosion of ferritic stainless steel in dual atmosphere at 600–800 °C

2018 ◽  
Vol 392 ◽  
pp. 129-138 ◽  
Author(s):  
Patrik Alnegren ◽  
Mohammad Sattari ◽  
Jan-Erik Svensson ◽  
Jan Froitzheim
Keyword(s):  
Stainless Steel ◽  
Temperature Dependence ◽  
Ferritic Stainless Steel ◽  
Dual Atmosphere

Impact of isothermal aging on fine pitch BGA packages with Sn-Ag-Cu solder interconnects

2010 ◽  
Vol 2010 (1) ◽  
pp. 000298-000305
Author(s):  
Tae-Kyu Lee ◽  
Weidong Xie ◽  
Thomas R. Bieler ◽  
Kuo-Chuan Liu ◽  
Jie Xue
Keyword(s):  
Thermal Cycling ◽  
Microstructure Evolution ◽  
Isothermal Aging ◽  
Substrate Surface ◽  
Solder Interconnects ◽  
Surface Finishes ◽  
Bga Packages ◽  
Fine Pitch ◽  
Solder Balls

The interaction between isothermal aging and long-term reliability of fine pitch ball grid array (BGA) packages with Sn-3.0Ag-0.5Cu (wt%) solder ball interconnects are investigated. In this study, 0.4mm fine pitch packages with 0.3mm diameter Sn-Ag-Cu solder balls are used. Two different die sizes and two different package substrate surface finishes are selected to compare the internal strain impact and alloy effect, especially the Ni effect during thermal cycling. To see the thermal impact on the thermal performance and long-term reliability, the samples are isothermally aged and thermal cycled from 0 to 100°C with a 10minute dwell time. Based on weibull plots for each aging condition, the lifetime of the package reduced approximately 44% with 150°C aging precondition. The microstructure evolution is observed during thermal aging and thermal cycling with different phase microstructure transformations between electrolytic Ni/Au and OSP surface finishes, focusing on the microstructure evolution near the package side interface. Different mechanisms after aging at various conditions are observed, and their impacts on the fatigue life of solder joints are discussed.

FEA Based Reliability Predictions for PBGA Packages Subjected to Isothermal Aging Prior to Thermal Cycling

2015 ◽  
Author(s):  
Munshi Basit ◽  
Mohammad Motalab ◽  
Jeffrey C. Suhling ◽  
John L. Evans ◽  
Pradeep Lall
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Isothermal Aging ◽  
Material Behavior ◽  
Lead Free ◽  
Stress Strain ◽  
Solder Material ◽  
Free Solder ◽  
Temperature Aging

The microstructure, mechanical response, and failure behavior of lead free solder joints in electronic assemblies are constantly evolving when exposed to isothermal aging and/or thermal cycling environments. In our prior work on aging effects, we have demonstrated that the observed material behavior degradations of Sn-Ag-Cu (SAC) lead free solders during room temperature aging (25 C) and elevated temperature aging (50, 75, 100, 125, and 150 C) were unexpectedly large. The measured stress-strain data demonstrated large reductions in stiffness, yield stress, ultimate strength, and strain to failure (up to 50%) during the first 6 months after reflow solidification. In this study, we have used both accelerated life testing and finite element modeling to explore how prior isothermal aging affects the overall reliability of PBGA packages subjected to thermal cycling. In the experimental work, an extensive test matrix of thermal cycling reliability testing has been performed using a test vehicle incorporating several sizes (5, 10, 15, 19 mm) of BGA daisy chain components with 0.4 and 0.8 mm solder joint pitches (SAC305). PCB test boards with 3 different surface finishes (ImAg, ENIG and ENEPIG) were utilized. In this paper, we concentrate on the reporting the results for a PBGA component with 15 mm body size. Before thermal cycling began, the assembled test boards were divided up into test groups that were subjected to several sets of aging conditions (preconditioning) including 0, 6, and 12 months aging at T = 125 °C. After aging, the assemblies were subjected to thermal cycling (−40 to +125 °C) until failure occurred. The Weibull data failure plots have demonstrated that the thermal cycling reliabilities of pre-aged assemblies were significantly less than those of non-aged assemblies. A three-dimensional finite element model of the tested 15 mm PBGA packages was also developed. The cross-sectional details of the solder ball and the internal structure of the BGA were examined by scanning electron microscopy (SEM) to capture the real geometry of the package. Simulations of thermal cycling from −40 to 125 C were performed. To include the effects of aging in the calculations, we have used a revised set of Anand viscoplastic stress-strain relations for the SAC305 Pb-free solder material that includes material parameters that evolve with the thermal history of the solder material. The accumulated plastic work (energy density dissipation) was used is the failure variable; and the Darveaux approach to predict crack initiation and crack growth was applied with aging dependent parameters to estimate the fatigue lives of the studied packages. We have obtained good correlation between our new reliability modeling procedure that includes aging and the measured solder joint reliability data. As expected from our prior studies on degradation of SAC material properties with aging, the reliability reductions were more severe for higher aging temperature and longer aging times.

Two-Station Embossing Process for Rapid Fabrication of Polymer Microstructures

2005 ◽  
Author(s):  
Donggang Yao ◽  
Allen Y. Yi ◽  
Lei Li ◽  
Pratapkumar Nagarajan
Keyword(s):  
Thermal Cycling ◽  
Elevated Temperatures ◽  
Polymeric Materials ◽  
Large Mass ◽  
Hot Embossing ◽  
Electrical Heating ◽  
Thermal Mass ◽  
Mold Surface ◽  
Cycle Times ◽  
Rapid Thermal Cycling

The hot embossing technique is becoming an increasingly important alternative to silicon-and glass-based microfabrication technologies. The advantage of hot embossing can be mainly attributed to the versatile properties and mass production capability of polymeric materials. However, because of the use of a large mass in thermal cycling, hot embossing is subject to substantially longer cycle times than those in traditional thermoplastic molding processes.1 The longer dwell time at elevated temperatures could further result in degradation of the embossing polymer, especially for thermally sensitive polymers. The problem exacerbates when thick polymer substrates are used. To address this problem, rapid thermal cycling of the tool is needed. One method for rapid thermal cycling is to employ a low-thermal-mass multilayer mold with electrical heating elements installed right beneath the mold surface.2 This method, however, is complex in nature and may be prone to problems caused by mismatching of thermal and mechanical properties between different layers.

scholarly journals Thermal cycling induced stress–assisted sigma phase formation in super duplex stainless steel

2019 ◽  
Vol 182 ◽  
pp. 108003 ◽  
Author(s):  
Jian-Sin Li ◽  
Guan-Ju Cheng ◽  
Hung-Wei Yen ◽  
Liberty T. Wu ◽  
Yo-Lun Yang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Thermal Cycling ◽  
Duplex Stainless Steel ◽  
Phase Formation ◽  
Sigma Phase ◽  
Super Duplex Stainless Steel ◽  
Induced Stress
Sign in / Sign up

Export Citation Format

Share Document