机械振动对ZL205A合金铸件低压铸造热裂的影响
发布时间：2018-11-06 10:52
【摘要】：本课题采用机械振动和低压铸造相结合的原理自主研究设计了低压振动铸造平台。利用数值模拟手段,研究了波动载荷对低压铸造温度场、应力场和热裂形成倾向的影响。以ZL205A合金作为实验材料,研究了不同振动参数下的机械振动对ZL205A合金铸件低压铸造热裂的影响规律。低压振动铸造平台包括振动模块、低压模块、测温模块和模具模块四个主要部分。振动模块以惯性式偏心轮振动电机作为振源,可以按需求调节机械振动的频率、振幅,利用测温模块控制起振温度。通过对ZL205A低压铸造过程施加波动载荷的数值模拟,预测了铸件热裂倾向最大的位置。通过比较不施加波动载荷和施加振动载荷铸件的应力分布,发现施加波动载荷后,热节处应力减小,以此减小铸件的热裂倾向。通过在低压条件下浇注了12组振动试样,对铸件的裂纹深度进行分别测量,利用正交分析手段得到了振动频率、振动振幅、铸件尺寸和起振温度对铸件表面裂纹的大小影响规律。研究发现:细杆的直径大小对裂纹的影响最大,其次是振动频率,对裂纹深度影响最小的是振动振幅。从正交实验表中我们可以十分容易的找到低压铸造施加机械振动的最佳振动参数,即当振动频率为15Hz、振幅为0.5mm、细杆直径为30mm、起振温度为650℃的时候,铸件产生热裂纹的倾向最小。通过测量铸件的收缩量,得到铸件内部应力随振动参数不同而产生的变化大小,从而进一步判断铸件内部的热裂倾向。综合分析来看,机械振动对低压铸件热裂影响倾向最小的工艺为频率15Hz、振幅0.5mm、高温下浇注。
[Abstract]:Based on the principle of mechanical vibration and low-pressure casting, the platform of low-pressure vibration casting is designed. The influence of fluctuating load on temperature field, stress field and hot crack forming tendency of low pressure casting was studied by numerical simulation. The effect of mechanical vibration on hot cracking of ZL205A alloy castings in low pressure casting was studied with ZL205A alloy as experimental material. Low-pressure vibration casting platform consists of four main parts: vibration module, low pressure module, temperature measurement module and die module. The vibration module takes the inertial eccentric wheel vibration motor as the vibration source, can adjust the frequency and amplitude of the mechanical vibration according to the demand, and use the temperature measurement module to control the starting temperature. By numerical simulation of fluctuating load applied in ZL205A low pressure casting process, the position of the largest hot cracking tendency was predicted. By comparing the stress distribution of castings with no wave load and vibration load, it is found that the stress at hot joint decreases after the application of fluctuating load, thereby reducing the hot cracking tendency of castings. By pouring 12 groups of vibrating samples at low pressure, the crack depth of castings was measured, and the vibration frequency and vibration amplitude were obtained by means of orthogonal analysis. The influence of casting size and vibration temperature on the surface crack size of castings. It is found that the diameter of the rod has the greatest influence on the crack, followed by the vibration frequency, and the vibration amplitude has the least effect on the crack depth. From the orthogonal test table, we can easily find the best vibration parameters applied in low pressure casting, that is, when the vibration frequency is 15 Hz, the amplitude is 0.5 mm, the diameter of the rod is 30 mm, the starting temperature is 650 鈩，
本文编号：2314066
[Abstract]:Based on the principle of mechanical vibration and low-pressure casting, the platform of low-pressure vibration casting is designed. The influence of fluctuating load on temperature field, stress field and hot crack forming tendency of low pressure casting was studied by numerical simulation. The effect of mechanical vibration on hot cracking of ZL205A alloy castings in low pressure casting was studied with ZL205A alloy as experimental material. Low-pressure vibration casting platform consists of four main parts: vibration module, low pressure module, temperature measurement module and die module. The vibration module takes the inertial eccentric wheel vibration motor as the vibration source, can adjust the frequency and amplitude of the mechanical vibration according to the demand, and use the temperature measurement module to control the starting temperature. By numerical simulation of fluctuating load applied in ZL205A low pressure casting process, the position of the largest hot cracking tendency was predicted. By comparing the stress distribution of castings with no wave load and vibration load, it is found that the stress at hot joint decreases after the application of fluctuating load, thereby reducing the hot cracking tendency of castings. By pouring 12 groups of vibrating samples at low pressure, the crack depth of castings was measured, and the vibration frequency and vibration amplitude were obtained by means of orthogonal analysis. The influence of casting size and vibration temperature on the surface crack size of castings. It is found that the diameter of the rod has the greatest influence on the crack, followed by the vibration frequency, and the vibration amplitude has the least effect on the crack depth. From the orthogonal test table, we can easily find the best vibration parameters applied in low pressure casting, that is, when the vibration frequency is 15 Hz, the amplitude is 0.5 mm, the diameter of the rod is 30 mm, the starting temperature is 650 鈩，
本文编号：2314066
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