B93合金的时效析出特性研究

对B93合金进行了X射线衍射物相分析及晶格常数的精确测量,定性地表征时效过程中MgZn2相的析出,并通过测试B93合金在等速加热和等温延时过程中电阻率的变化来模拟时效第二相粒子的析出过程.结果表明,等速加热时效时,由于不同温度下合金析出相的析出程度不同,电阻率随着温度的变化而变化;在同一温度保温时,随着时间的延长,电阻率减小,当析出完全后,电阻率保持在同一水平不再变化;而时效温度越高,电阻率越大,电阻率曲线下降的速率越快,到达水平值所需要的时间也就越短.同时,根据电阻率随温度变化曲线模拟出电阻率计算公式.

Aging Precipitation Characteristics of B93 Alloy

Precipitation of MgZn_2 phase in B93 forgings during aging process was characterized by qualitative optical microscope (OM) observation, X-ray diffraction (XRD) and precision measurement of lattice constant, and precipitation of second phase in the alloy during aging process was described by examining the change of resistivity of B93 alloy during continuous heating process and delayed time process. The results reveal that resistivity of the alloy varies with changing in temperature during continuous heating process as a result of different precipitation rate of precipitates in the alloy at different temperatures. At a given holding temperature, with increasing in holing time, resistivity is decreased, and it keeps a constant value after complete precipitation. With increasing in aging temperature, resistivity is increased and descending rate of the resistivity curves is quickened, so the time to reach the constant value becomes shorter. Meanwhile, a calculation formula for resistivity is presented based on the curves of resistivity to temperature.