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High damping capacity materials are useful in attenuating vibrations in mechanical structures such as functional automotive bracketry. The intrinsic damping properties of zinc alloys have only recently been systematically measured. Low and high frequency damping experiments have been conducted on die cast zinc alloys. and damping capacity has been measured as a function of temperature at high frequencies. The alloys show excellent damping properties over the range from 5 Hertz to a few hundred Hertz. for service applications from 40-80°C (104-176°F).

SIMILAR SPECIFICATIONS—UNS Z33521, former SAE 903, ingot is similar to ASTM B 240-79, Alloy AG40A; and UNS Z33520, former SAE 903, die casting is similar to ASTM B 86-76, Alloy AG40A. UNS Z35530, former SAE 925, ingot is similar to ASTM B 240-79, Alloy AC41A; and UNS Z35531, former SAE 925, die casting is similar to ASTM B 86-82a, Alloy AC41A.

The ZA series of zinc alloys produce high strength die castings with the same cast-to size capability as the well proven SAE 903 alloy. The enhanced properties have been utilised in the two engine components described in this paper. ZA 27 has been used for the tooth belt drive camshaft pulley of a motorcycle engine and ZA8 has been used for the temperature resistant housing of a car ignition distributor.

This specification covers a zinc alloy in the form of die castings.

This specification covers a zinc alloy in the form of die castings.

This specification covers a zinc alloy in the form of die castings.

Internal combustion engines development with increased complexity due to CO2 reduction and emissions regulation, while reducing costs and duration of development projects, makes numerical simulation essential. 1D engine simulation software response for the gas exchange process is sufficiently accurate and quick. However, combustion simulation by Wiebe function is poorly predictive. The objective of this paper is to compare different approaches for 0D Spark Ignition (SI) modeling. Versions of Eddy Burn Up, Fractal and Flame Surface Density (FSD) models have been coded into GT-POWER platform, which connects thermodynamics, gas exchange and combustion sub-models. An initial flame kernel is imposed and then, the flame front propagates spherically in the combustion chamber. Flame surface is tabulated as a function of piston position and flame radius. The modeling of key features of SI combustion such as laminar flame speed and thickness and turbulence was common.

A precise estimation of the recirculated exhaust gas rate and oxygen concentration as well as a predictive evaluation of the possible EGR unbalance among cylinders are of paramount importance, especially if non-conventional combustion modes, which require high EGR flow-rates, are implemented. In the present paper, starting from the equation related to convergent nozzles, the EGR mass flow-rate is modeled considering the pressure and the temperature upstream of the EGR control valve, as well as the pressure downstream of it. The restricted flow-area at the valve-seat passage and the discharge coefficient are carefully assessed as functions of the valve lift. Other models were fitted using parameters describing the engine working conditions as inputs, following a semi-physical and a purely statistical approach. The resulting models are then applied to estimate EGR rates to both conventional and non-conventional combustion conditions.

The thermal deflection associated with the conventional die heat treating procedure usually requires extra die grinding process to fine-tune the die surface. Due to the size of the production die, the grinding is time consuming and is not cost effective. The goal of the study is to develop a new die heat treating process utilizing the flexible laser heat treatment, which could serve the same purpose as the conventional die heat treating and avoid the thermal deflection. The unique look of the developed zebra pattern laser heat treating process is defined as the Zebra Line. The heat-treating parameters and processes were developed and calibrated to produce the laser heat treating on laboratory size dies, which were subjected to the die wear test in the laboratory condition. The USS HDGI 980 XG3TM steel was selected to be carried out on the developmental dies in the cyclic bend die wear test due to its high strength and coating characteristic.

ZINCROMETAL usage in the automotive sector has increased rapidly since 1972. As one might expect, this has led to considerable interest in the details of producing this product. In order to fulfill this expressed need, a description of the manufacture of ZINCROMETAL is presented here. Since the process is inextricably involved with a variety of quality control and quality assurance testing procedures, they are incorporated into this paper also. Finally, a long but incomplete listing of parts where ZINCROMETAL has been applied in auto bodies is reviewed.

This specification covers the engineering requirements for electrodepositton of zinc and the properties of the deposit.

Because of the drastic chilling involved in die casting and the fact that the solid solubilities of both aluminum and copper in zinc change with temperature, these alloys are subject to some aging changes, one of which is a dimensional change. Both of the alloys undergo a slight shrinkage after casting, which at room temperature is about two-thirds complete in five weeks. It is possible to accelerate this shrinkage by a stabilizing anneal, after which no further changes occur. The recommended stabilizing anneal is 3 to 6 h at 100 °C (212 °F), or 5 to 10 h at 85 °C (185 °F), or 10 to 20 h at 70 °C (158 °F). The time in each case is measured from the time at which the castings reach the annealing temperature. The parts may be air cooled after annealing. Such a treatment will cause a shrinkage (0.0004 in per in) of about two-thirds of the total, and the remaining shrinkage will occur at room temperature during the subsequent few weeks.

SIMILAR SPECIFICATIONS—UNS Z33521, former SAE 903, ingot is similar to ASTM B 240-79, Alloy AG40A; and UNS Z33520, former SAE 903, die casting is similar to ASTM B 86-76, Alloy AG40A. UNS Z35530, former SAE 925, ingot is similar to ASTM B 240-79, Alloy AC41A; and UNS Z35531, former SAE 925, die casting is similar to ASTM B 86-82a, Alloy AC41A.