Nondestructive characterization of elastic modulus of APS Ni–5Al/10hBN coating on stainless steel 304 under high temperature

AbstractJoining of thin sheets (0.5 mm) of stainless steel 304 and 17-4PH through resistance spot welding is highly challenging especially when joint is used for high temperature applications. Various combinations of stainless steel sheets of thickness 0.5 mm are spot welded and tested at room temperature as well as at high temperatures (800 K, 1,000 K, 1,200 K). Parent metal as well as spot welded joints are tested and characterized. It is observed that joint strength of 17-4PH steel is highest and then dissimilar steel joint of 17-4PH with SS-304 is moderate and of SS-304 is lowest at all the temperatures. Joint strength of 17-4PH steel is found to be >80% of parent metal properties up to 1,000 K then drastic reduction in strength is noted at 1,200 K. Gradual reduction in strength of SS-304 joint with increase in temperature from 800 to 1,200 K is noted. At 1,200 K, joint strength of all combinations of joints is found to be nearly same. Microstructural evaluation of weld nugget after testing at different temperatures shows presence of tempered martensite in 17-4PH containing welds and homogenized structure in stainless steel 304 weld.

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Characterization of stainless steel 304 tubing

10.2172/125388 ◽

1995 ◽

Author(s):

A.J. Sunwoo ◽

M.A. Brooks ◽

J.E. Kervin

Keyword(s):

Stainless Steel ◽

Stainless Steel 304

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Metallographic Characterization of Transgranular Stress Corrosion Cracking on Type316L Stainless Steel in High Temperature and High Pressure Water Environment

ECS Meeting Abstracts ◽

10.1149/ma2012-02/22/2190 ◽

2012 ◽

Keyword(s):

High Pressure ◽

Stainless Steel ◽

High Temperature ◽

Stress Corrosion ◽

Stress Corrosion Cracking ◽

Water Environment ◽

Corrosion Cracking ◽

Pressure Water

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Packaged Parylene-Diaphragm Piezoelectric Microspeaker

10.1115/imece2000-1079 ◽

2000 ◽

Author(s):

Cheol-Hyun Han ◽

Eun Sok Kim

Keyword(s):

Stainless Steel ◽

Elastic Modulus ◽

Vibration Amplitude ◽

Sound Pressure ◽

Pressure Level ◽

Zno Film ◽

Acoustic Transducer ◽

Low Elastic Modulus ◽

Pressure Output

Abstract This paper describes our first demonstration of the parylene-diaphragm piezoelectric acoustic transducer as a fully functional microspeaker and also characterization of its vibration amplitude and sound pressure output. The piezoelectric microspeaker is built on a 1.5 μm thick parylene diaphragm (5,000*5000 μm2 square diaphragm micromachined in a silicon substrate) with electrodes and piezoelectric ZnO film. The parylene (a polymer material) has very low elastic modulus (about 50 to 100 times smaller than conventional diaphragm materials such as silicon nitride, stainless steel, etc), and is an outstanding material for a speaker application. The speaker is shown to produce a maximum sound-pressure level of 91 dB SPL into 2 cm3 acoustic coupler at a resonant frequency of 9.5 kHz. The vibration amplitude at that frequency is measured to be 1.8 μm with a laser doppler meter. Proper packaging of the microspeaker improves the sound output by preventing the cancellation of the sound output from the backside that has 180 degree out of phase.

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