Dynamic Behavior and High Speed Machining of Ti-6246 and Alloy 625 Superalloys: Experimental and Modeling Approaches

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

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ANACONDA ALLOY 360

Alloy Digest ◽

10.31399/asm.ad.cu0447 ◽

1982 ◽

Vol 31 (11) ◽

Keyword(s):

Corrosion Resistance ◽

Physical Properties ◽

High Speed ◽

Heat Treating ◽

High Speed Machining ◽

Copper Base ◽

Screw Machine ◽

Medium Strength ◽

Machining Operations ◽

Strength And Ductility

Abstract ANACONDA Alloy 360 is a leaded brass and is the alloy most often used for high-speed machining operations; it fills most of the needs for such purposes. Alloy 360 is the standard free-cutting brass and its machinability has become the standard by which all other copper-base alloys are rated. It has medium strength and ductility. Alloy 360 is used for hardware such as gears and pinions where excellent machinability is of prime importance and for all types of automatic high-speed screw-machine products. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-447. Producer or source: Anaconda American Brass Company.

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Milling cutters for high speed machining. Safety requirements

10.3403/02361030 ◽

2001 ◽

Keyword(s):

High Speed ◽

High Speed Machining ◽

Safety Requirements

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Research on High-Speed Cutting of Cr12MoV Hardened Steel - A Review

Recent Patents on Engineering ◽

10.2174/1872212115999201201111251 ◽

2020 ◽

Vol 15 ◽

Author(s):

Fei Sun ◽

Guohe Li ◽

Qi Zhang ◽

Meng Liu

Keyword(s):

High Speed ◽

Cutting Temperature ◽

High Hardness ◽

High Strength ◽

Hardened Steel ◽

Parameters Optimization ◽

Future Research ◽

High Speed Machining ◽

Machined Surface ◽

Stamping Die

: Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.

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