On the onset of steady state during transient adhesive wear

This paper reports experimental data on the wear of high-speed steel bimetal bandsaw blades cutting austenitic 17-7 stainless steel bars. Several different methods of assessing the wear modes and mechanisms are evaluated; Cutting and thrust force components, Set width, Kerf width, “Out-of-square” cutting, Wear modes and mechanisms and Chip characteristics. The wear mode established in the current work when bandsawing austenitic stainless steel with a bimetal blade is flank and corner wear together with formation of a cutting edge radius. The cutting edge radius increases as the wear progresses, reaching 25-50 mm after 300 cut sections. The established wear mechanism for the initial stages of wear is mild adhesive wear of the flank surface together with built-up edge formation and break-down. As the wear reaches steady-state the mechanism is adhesive wear of the flank surface with tempering/softening of high-speed steel layers. When the wear reached the steady-state region the level of thrust and cutting force were equal and relatively high. The kerf width appears to be less than the total set width of the blade, meaning that there is compression of the set teeth as they pass through the kerf. There is segmented chip formation with an increasing amount of vibration as the teeth wear, probably due to the increasing size of cutting edge radius. This work should be of great interest to the tool designer and user associated with bandsaws.

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Prediction of Steady State Adhesive Wear in Spur Gears Using the EHL Load Sharing Concept

Journal of Tribology ◽

10.1115/1.3075859 ◽

2009 ◽

Vol 131 (2) ◽

Cited By ~ 23

Author(s):

S. Akbarzadeh ◽

M. M. Khonsari

Keyword(s):

Steady State ◽

Wear Rate ◽

Thermal Effects ◽

Sliding Wear ◽

Adhesive Wear ◽

Load Sharing ◽

Spur Gears ◽

Wear Model ◽

Wear Calculation ◽

Simulation Results

The concept of load sharing between asperities and fluid film is applied in conjunction with lubricated sliding wear formulation proposed by Wu and Cheng (1991, “A Sliding Wear Model for Partial-EHL Contacts,” ASME J. Tribol., 113, pp. 134–141; 1993, “Sliding Wear Calculation in Spur Gears,” ASME J. Tribol., 115, pp. 493–500) to predict the steady state adhesive wear in gears. Thermal effects are included using a simplified thermoelastohydrodynamic analysis. The prediction of the model is verified by comparing simulation results with published experimental data pertinent to steady state wear rate. The main advantages of this method are the accuracy and the remarkable computational efficiency. The results of parametric simulation study are presented to investigate the effect of speed and surface roughness on a portion of load carried by asperities and wear rate.

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Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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Continuous hydrogenolysis of acetal-stabilized lignin in flow

Green Chemistry ◽

10.1039/d0gc02928a ◽

2021 ◽

Author(s):

Wu Lan ◽

Yuan Peng Du ◽

Songlan Sun ◽

Jean Behaghel de Bueren ◽

Florent Héroguel ◽

...

Keyword(s):

Steady State ◽

Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

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