Proposal of an Evaluating Method on Lubrication

Isogawa, Sachihiro; Kimura, Atsuyoshi; Tozawa, Yasuhisa

doi:10.1016/s0007-8506(07)61200-1

Cited by 48 publications

(17 citation statements)

References 6 publications

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“…The SCT was developed to realize a nearly homogeneously distributed contact normal stress and surface enlargement [17]. This differentiates the SCT from other tribometers such as the Double Cup Extrusion Test [18], the Ring Compression Test [19] or the Spike Test [20]. Results derived from the SCT are in good quantitative agreement with results gained with other tribometers [21].…”

Section: Test Setupmentioning

confidence: 83%

Wear Prediction in Oscillating Cold Forging Processes

Groche

Schmidt

2020

Tribol Lett

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Oscillating forming processes allow forming with reduced process forces when liquid lubricants are used. They are industrially applied as oscillating cold forging processes for the production of splines. Previous investigations revealed that the force reduction is provoked by relubrication of the workpiece—tool contact zone. So far, the effect of the oscillation on tool wear remains unknown. The results presented in this paper show that the wear critical region of the tool is the calibration zone. Tool wear is emulated on a test bench under loads of representative cold forging processes. The results disclose several relevant phenomena. Friction conditions can vary considerably in the course of the oscillations. Wear protection layers are effective measures to prolong tool life also under these conditions. Prediction of wear development based on established models fails due to neglecting the local state of lubrication. Graphical Abstract

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Section: Test Setupmentioning

confidence: 83%

Wear Prediction in Oscillating Cold Forging Processes

Groche

Schmidt

2020

Tribol Lett

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“…From Table 3, it can be found that H 0 high (m = 0.3) is larger than H 0 low (m = 0.1) in some schemes including schemes 9-14 and 16, and it means that the spike height increases with the friction factor which is different from conventional discussions. 11,22 Therefore, further discussions need to be carried out. So, all results are classified into three groups according to the level of spike height difference, that is, schemes 13, 14 in group A, schemes 11, 12 in group B, and schemes 9, 10, and 16 in group C, respectively.…”

Section: Fe-based Design Of Experimentsmentioning

confidence: 99%

Investigation of tribological condition in cold forging using an optimized design of spike forging test

Zhao

2015

Advances in Mechanical Engineering

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The spike forging test is still commonly used although there are some new tribology test methods, but each designer would like to give their own parameters. Considering the spike height difference between low friction and high friction as the evaluation index, an optimal spike forging test developed using finite element simulations based on orthogonal optimization method and sensitivity analysis of tribological conditions of selected key design parameters was carried out. The spike height does not always monotonically decrease with the increase in friction factor in the scheme with improper parameters; therefore, the design of spike forging test should be critically evaluated before assessing tribological conditions. According to the optimized parameters, a simplified set-up of spike forging test was designed, and two retainers with a clearance fit and the billet with a chamfer were prepared to position the test billet. Finally, four different tribological conditions, including dry polytetrafluoroethylene lubricant, multipurpose grease, VG32 oil, and dry condition, in aluminum forging were chosen as a case study for the optimized design of spike forging test, and correspondingly, the lubricating effect was distinguished.

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“…It utilizes a hydraulic press to apply the necessary contact normal stresses up to 3,000N/mm², surface enlargements up to 11 and relative velocities up to 500 mm/s which may occur during cold forging. In comparison to other tribometers like the Double-Cup-Extrusion Test [14], the Ring Compression Test [15] or the Spike Test [16], it is possible to set a specific and nearly homogeneously distributed contact normal stress and surface enlargement. These are important parameters for a reliable determination of the friction coefficient.…”

Section: Sliding Compression Testmentioning

confidence: 99%