جستجوی مقالات مرتبط با کلیدواژه "سرسیلندر" در نشریات گروه "مکانیک"

Due to the significant advancements in additive manufacturing methods in various industries, additive manufacturing is expected to create changes in the traditional foundry industry and improve it so that it can grow rapidly. Fast, integrated and low-cost manufacturing for high-performance industrial parts and complex shapes. Additive manufacturing technology, commonly used in sand mold and core making, can speed up the new product development process. In this article, by measuring the sand body of the intake port in the cylinder head of the newly developed engine produced by the binder injection process, it was compared with the sand body produced by the cold box process and the results were analyzed and evaluated. The results show that the average of dimensional and geometrical accuracy of the produced part by the binder jetting process are improved about 50 percent compared to the cold mechanical method. However, the results of roughness measurement and surface morphology do not show much difference between these two processes, but due to the ability to control parameters in the 3D printing process, it is possible to perform improvement in surface quality.

In the present article, T4 and T6 heat treatments carried out to improve microstructure and mechanical properties (hardness and tensile) of Al-Si-Cu alloys (A380 alloy, which has been used in engine cylinder heads). For this purpose, solution annealing was performed at 490 ºC for 5 h. The T6 aging was executed at 180, 200, 220, 240 ºC for 1, 3, 5, 7 h. Hardness experimental results showed that optimum values for the T6 aging temperature and time are generally 200˚C and 3 h, respectively, as the hardness increased. Evaluation of the microstructures and fractured surfaces were performed with optical and scanning electron microscopes. After T6 treatment, tensile strength increased from 245 to 255 MPa and hardness from 88 to 95 Vickers. By applying T6 process in optimized tempeIn current paper two different regimes of heat treatments, namely T4 and T6 treatments of Al-Si-Cu alloy used in engine cylinder head were investigated and the effects and significance of time and temperature on microstructure and mechanical properties of the material were studied and compared. For this purpose, solution annealing was performed at 490 ºC for 5 h. The T6 aging was executed at 180, 200, 220, 240 ºC for 1, 3, 5, 7 h. Hardness testing results revealed that the optimum hardness is obtained for T6 at 200˚C and 3h, respectively, as the hardness increased. Evaluation of the microstructures and fractured surfaces were performed with optical and scanning electron microscopes. After T6 treatment, tensile strength increased from 245 to 255 MPa and hardness from 88 to 95 Vickers. By applying T6 process in optimized temperature and time, the hardness and tensile strengths of Al-Si-Cu alloy was enhanced from 10.5% compared to that of the T4 processes. The sensitivity analysis indicated that effect of the aging temperature is more significant in comparison to other parameters.
rature and time, the hardness and tensile strengths of Al-Si-Cu alloy was enhanced from 10.5% compared to that of the T4 processes. The sensitivity analysis indicated that effects of the aging temperature are more significant in comparison to other parameters

Nowadays, the technology intends to use materials such as magnesium alloys due to their high strength to weight ratio in engine components. As usual, engine cylinder heads and blocks has made of various types of cast irons and aluminum alloys. However, magnesium alloys has physical and mechanical properties near to aluminum alloys and reduce the weight up to 40 percents. In this article, a new low cycle fatigue lifetime prediction model is presented for a magnesium alloy based on energy approach and to obtain this objective, the results of low cycle fatigue tests on magnesium specimens are used. The presented model has lower material constants in comparison to other criteria and also has proper accuracy; because in energy approaches, a plastic work-lifetime relation is used where the plastic work is the multiple of stress and plastic strain. According to cyclic softening behaviors of magnesium and aluminum alloys, plastic strain energy can be proper selection, because of being constant the product value of stress and plastic strain during fatigue loadings. In addition, the effect of mean stress is applied to the low cycle fatigue lifetime prediction model by using a correction factor. The results of presented models show proper conformation to experimental results.

Safety of machinery parts, it is important for users and defects as one of the most important parts of threats to the health of the pieces have always been considered. In this paper, a new method based on the use of artificial neural networkDetection Pridecylinder head into mechanical waves is presented. Then, for verification and validation of the finite element model , modal test piece , and after confirming the fault simulation is performed on a finite element model. Force simulation model (FEM) acceleration signal - the healthy and faulty models calculated for each fault. And with the signing of mechanical defects ( acceleration difference between healthy and faulty models ) and to train a multilayer perceptron neural network (MLP) , the difference between the acceleration signal to the associated fault location. Detectionautomotive cylinder head (estimated fault location) has been. The results of the neural network capabilities designed to estimate the fault location on a good show.