Prapas Kunnam
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Chaowalit Limmaneevichitr
材料科学技术（英文）
This paper presents the effects of different process parameters in producing Al-5Ti-1B grain refiner, i.e. various sequences and reaction time, on grain refinement efficiency of aluminum castings. It was found that different process parameters resulted in different morphology and size distribution of TiAl3 and TiB2 in grain refiner. The experiment was carried out by adding KBF4 and K2TiF6 to molten aluminum. The melting temperature was controlled at 800℃ in an electric resistance furnace. Three different sequences of KBF4 and K2TiF6 additions were applied, i.e., adding KBF4 before K2TiF6, adding K2TiF4 before KBF4 and mixing both KBF4 and K2TiF6 before adding to molten aluminum. Three different holding time at 1 min, 30 min and 60 min were applied. The results showed that no significant difference of morphology and size distribution was found by varying three different sequences. Whereas, the different holding time provided major differences in both morphology and size distribution, which are technically expectable from diffusion and agglomeration between particles resulting in larger particle size and wider range of size distribution of TiAl3 and TiB2. If the reaction time was longer than 30 min, morphology of both TiAl3 and TiB2 became too large. If the reaction time was too short, less reaction between TiAl3 and TiB2 to form would be obtained. For grain refinement efficiency, it was found that mixing KBF4 and K2TiF6 before adding to molten aluminum with a holding time of 30 min resulted in best grain refinement efficiency.
关键词:
Grain refinement
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刘洋
,
李鹏南
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陈明
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邱新义
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唐玲艳
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2016.05.010
针对碳纤维复合材料钻孔时易产生撕裂、毛刺等缺陷的特点,采用双锋角钻头为研究对象,从横刃、第一主切削刃和第二主切削刃对孔入、出口缺陷的影响和加工参数对撕裂因子的影响规律等方面分析双锋角钻头钻孔特点,并与普通麻花钻进行对比.结果表明:在相同的加工参数下,双锋角钻头双主切削刃加工特点降低了入、出口钻削轴向力,有效抑制了入、出口撕裂、毛刺等缺陷产生,更适合于钻削碳纤维复合材料.主轴转速增大有利于减小撕裂因子,随着进给速度的增加撕裂因子呈增大的趋势.采用多元线性回归方法建立了试验两种钻头钻孔入、出口的撕裂因子与加工参数之间的回归预测模型.
关键词:
双锋角钻头
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碳纤维复合材料
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撕裂
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加工参数
付延英
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翟贤超
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印雪梅
宇航材料工艺
doi:10.12044/j.issn.1007-2330.2017.02.009
为了研究工艺参数对金属激光直接成形零件质量的影响,通过正交试验的方法对单道单层GH3625合金激光直接成形工艺进行了研究,主要探究了激光功率、扫描速度、送粉速度等参数对单道单层成形截面宽度和高度的影响规律,提出预测模型并做了验证.结果表明,在单道单层成形中,激光功率、送粉速度、扫描速度等工艺参数对单道宽度和高度具有不同程度的影响,其中,对于单道成形宽度和高度来讲,扫描速度对其影响最为明显.试验验证结果表明借助Minitab软件得到的线性回归模型是有效的.
关键词:
激光直接成形
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GH3625合金
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正交试验
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工艺参数
