scholarly journals Reliability of soldered joints for aerospace applications

2021 ◽  
Author(s):  
Brigitte Desrochers
Keyword(s):  
Quality Control ◽  
Aerospace Industry ◽  
Manufacturing Processes ◽  
Test Results ◽  
Specific Test ◽  
Mechanical Fatigue ◽  
Control Processes ◽  
Aerospace Applications ◽  
Space Industry ◽  
Electronic Assemblies

Known to be highly reliable, Tin-Lead (SnPb) solders have long been used in commercial and aerospace electronic assemblies due to their ability to withstand thermo-mechanical fatigue. A number of constitutive and thermo-mechanical life models for SnPb soldered joints can be used to determine whether a given board design meets the reliability requirements of a system. Known to be highly reliable, Tin-Lead (SnPb) solders have long been used in commercial and aerospace electronic assemblies due to their ability to withstand thermo-mechanical fatigue. A number of constitutive and thermo-mechanical life models for SnPb soldered joints can be used to determine whether a given board design meets the reliability requirements of a system.Due to environmental and toxicological concerns, government legislations worldwide now limit the use of Pb in manufacturing processes. Therefore, the aerospace industry must understand the reliability of proposed Pb-free alternatives prior to using them in the aerospace applications. In order to improve the space-readiness of Pb-free solders, a well-rounded collection of space-specific test results must be compiled and test-verified predictive life models must be developed. Finally, quality control processes associated with manufacturing, handling, and repairing Pb-free solders will have to be created before the space industry can make the transition from SnPb to Pb-free solders.

scholarly journals Reliability of soldered joints for aerospace applications

2021 ◽  
Author(s):  
Brigitte Desrochers
Keyword(s):  
Quality Control ◽  
Aerospace Industry ◽  
Manufacturing Processes ◽  
Test Results ◽  
Specific Test ◽  
Mechanical Fatigue ◽  
Control Processes ◽  
Aerospace Applications ◽  
Space Industry ◽  
Electronic Assemblies

Known to be highly reliable, Tin-Lead (SnPb) solders have long been used in commercial and aerospace electronic assemblies due to their ability to withstand thermo-mechanical fatigue. A number of constitutive and thermo-mechanical life models for SnPb soldered joints can be used to determine whether a given board design meets the reliability requirements of a system. Known to be highly reliable, Tin-Lead (SnPb) solders have long been used in commercial and aerospace electronic assemblies due to their ability to withstand thermo-mechanical fatigue. A number of constitutive and thermo-mechanical life models for SnPb soldered joints can be used to determine whether a given board design meets the reliability requirements of a system.Due to environmental and toxicological concerns, government legislations worldwide now limit the use of Pb in manufacturing processes. Therefore, the aerospace industry must understand the reliability of proposed Pb-free alternatives prior to using them in the aerospace applications. In order to improve the space-readiness of Pb-free solders, a well-rounded collection of space-specific test results must be compiled and test-verified predictive life models must be developed. Finally, quality control processes associated with manufacturing, handling, and repairing Pb-free solders will have to be created before the space industry can make the transition from SnPb to Pb-free solders.

Ultrasonic Casting of Off-Eutectic Tin Bismuth Solder Alloy for Mechanical Property Testing

2019 ◽  
Author(s):  
Laura Smith ◽  
Jeff Jennings
Keyword(s):  
Mechanical Properties ◽  
Mechanical Testing ◽  
Solder Alloy ◽  
Void Formation ◽  
Casting Process ◽  
Test Results ◽  
Good Test ◽  
Aerospace Applications ◽  
Solder Sample ◽  
Electronic Assemblies

Abstract Knowledge of solder mechanical properties is essential when designing electronic assemblies for use in harsh environments like those that exist in automotive or aerospace applications. However, information on solder mechanical properties is limited because fabricating material samples in a form factor used for typical mechanical testing is difficult. Conventional casting processes are prone to void formation and dross inclusion which can degrade the quality of test results acquired and often produce high degrees of variability. The current work describes in detail a novel casting process which seeks to address these solder sample fabrication issues. The non-conventional process applies ultrasonic excitation to eliminate voiding by breaking up dross inclusions and other voids, so none can form within the melt upon solidification. Cast ingots are machined then undergo non-destructive screening to ensure material consistency within the regions critical to producing good test results prior to being subjected to destructive mechanical testing. This ultrasonic casting process is applied to the testing of an off-eutectic Tin-Bismuth solder alloy and its ambient tensile and compressive stress versus strain properties are evaluated. The improvement in result repeatability for the various tested properties due to the ultrasonic casting are assessed and sample size considerations discussed.

Metacognitively guided retrieval and report (META-RAR): Quality control processes in recall

2009 ◽  
Author(s):  
Morris Goldsmith ◽  
Larry L. Jacoby ◽  
Vered Halamish ◽  
Christopher N. Wahlheim
Keyword(s):  
Quality Control ◽  
Control Processes

scholarly journals STL_Process: A .STL-based preprocessor for robot path planning in manufacturing and quality control processes

SoftwareX ◽  
2021 ◽  
Vol 15 ◽  
pp. 100725
Author(s):  
Abanti Shama Afroz ◽  
Francesco Inglese ◽  
Cesare Stefanini ◽  
Mario Milazzo
Keyword(s):  
Quality Control ◽  
Path Planning ◽  
Robot Path Planning ◽  
Control Processes ◽  
Robot Path

Mechanical Behavior of Ti-6Al-4V Manufactured by Electron Beam Additive Fabrication

2013 ◽  
Author(s):  
Leila Ladani ◽  
Lalit Roy
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Lead Time ◽  
Aerospace Industry ◽  
Tensile Tests ◽  
Test Results ◽  
Great Resistance ◽  
Additive Fabrication ◽  
Anisotropy Effect ◽  
The Cost

Additive Layer Fabrication, in particular Electron Beam Additive Fabrication (EBAF), has recently drawn much attention for its special usability to fabricate intricately designed parts as a whole. It not only increases the production rate which reduces the production lead time but also reduces the cost by minimizing the amount of waste material to a great extent. Ti6Al4V is the most common type of material that is currently being fabricated using EBAF technique. This material has been used in aerospace industry for several reasons such as excellent mechanical properties, low density, great resistance to corrosion, and non-magnetism. The effects of build direction of layers (namely, addition of layers along one of the x, y & z directions with respect to the build table) and the anisotropy effect caused by it has not been explored vigorously. This anisotropy effect has been investigated in this work. Different mechanical properties such as Yield Strength (YS), Ultimate Tensile Strength (UTS), and Modulus of Elasticity (E) of these three types of Ti6Al4V are determined using tensile tests and are compared with literature. The tensile test results show that YS and UTS for flat-build samples have distinguishably higher values than those of the side-build and top-build samples.

Friction-Instability: A New Design Parameter for Brakes

1971 ◽  
Vol 93 (4) ◽  
pp. 1225-1228 ◽  
Author(s):  
W. L. Starkey ◽  
T. G. Foster ◽  
S. M. Marco
Keyword(s):  
Quality Control ◽  
Coefficient Of Friction ◽  
Design Parameter ◽  
Control Device ◽  
Experimental Facility ◽  
Test Results ◽  
Effective Manner ◽  
The Coefficient Of Friction ◽  
Brake Lining ◽  
The Right

A new design parameter, friction-instability, is defined in this paper. Friction-instability is a variation in the coefficient of friction which may occur at any time during the life of a brake lining. A friction-index is defined which measures this variation. A lining which has a high friction index may tend to cause an automobile to swerve either to the right or to the left. A unique experimental facility is described by means of which the friction-instability characteristics of brake linings can be measured. Test results using this facility are presented and interpreted. The friction-index is proposed as a new parameter which should be taken into consideration when brakes are designed and, developed. This index should be particularly useful as a quality control device to insure that machines which use mass-produced braking systems will perform in a safe and effective manner.

scholarly journals Long-Term Calorie Restriction Enhances Cellular Quality-Control Processes in Human Skeletal Muscle

Cell Reports ◽  
2016 ◽  
Vol 14 (3) ◽  
pp. 422-428 ◽  
Author(s):  
Ling Yang ◽  
Danilo Licastro ◽  
Edda Cava ◽  
Nicola Veronese ◽  
Francesco Spelta ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Quality Control ◽  
Calorie Restriction ◽  
Human Skeletal Muscle ◽  
Control Processes

Frost Formation and its Density Behavior on Various Surfaces

2001 ◽  
Author(s):  
Cheolhwan Kim ◽  
Jongmin Shin ◽  
Alexei V. Tikhonov ◽  
Samchul Ha ◽  
Bongjun Choi
Keyword(s):  
Surface Energy ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Test Time ◽  
Test Results ◽  
Plate Temperature ◽  
Specific Test ◽  
Frost Formation ◽  
Frost Layer ◽  
Density Behavior

Abstract An experimental study has been conducted to investigate the effects of surface energy on frost formation. Test samples with three different surfaces of which Dynamic Contact Angles (DCA) are 23, 55 and 88 degrees are installed in a wind tunnel and exposed to a humid airflow. The thickness and the mass of frost layer are measured and used to calculate frost density while frost formation is visualized simultaneously with their measurements. Results show that frost density increases as time increases at specific test conditions. The air Reynolds number, the airflow humidity and the cold plate temperature are maintained at 12,000, 0.0042 kg/kg and −20 degrees Celsius, respectively. The surface with a lower DCA shows a higher frost density for a two-hour test, but no differences in frost density have been found after two hours of frost generation. Empirical correlations for thickness, mass and density are proposed as the functions of test time and surface energy. Visualization of frost generation was in good agreements with test results.

Developing, implementing and transferring lean quality initiatives from the aerospace industry to all industries

2000 ◽  
Vol 10 (4) ◽  
pp. 248-256 ◽  
Author(s):  
Dennis F.X. Mathaisel ◽  
Clare L. Comm
Keyword(s):  
Automobile Industry ◽  
Lean Manufacturing ◽  
Motor Vehicle ◽  
Aerospace Industry ◽  
Launch Vehicles ◽  
Quality Initiatives ◽  
Space Operations ◽  
Space Industry ◽  
The Us ◽  
Japanese Companies

Japanese companies, particularly Toyota, first began building quality into their products and becoming lean. Consequently, researchers associated with the international motor vehicle industry initially identified the “lean” manufacturing paradigm in the US automobile industry. Building upon their successes, the US aerospace industry initiated a study to ascertain whether a similar initiative focused on launch vehicles and spacecraft would bring value to military and commercial aerospace stakeholders in their ongoing efforts to be lean. This paper presents the findings of this investigation. It explores the relevance and value of the lean concepts to the US defense launch vehicle, spacecraft, and space operations industries, and it ascertains if there is interest within space industry firms in establishing a lean initiative similar to that of the automotive industry. Further, the relevance of lean manufacturing to other industries is considered.

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