Process parameter optimisation of laser clad iron based alloy: Predictive models of deposition efficiency, porosity and dilution
Process parameter optimisation of laser clad iron based alloy: Predictive models of deposition efficiency, porosity and dilution
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DOI：
10.1016/j.surfcoat.2018.05.054
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发表时间：
2018-09
影响因子：
5.4
通讯作者：
L. Reddy;S. P. Preston;P. Shipway;C. Davis;T. Hussain
中科院分区：
文献类型：
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作者：
L. Reddy;S. P. Preston;P. Shipway;C. Davis;T. Hussain
作为商业发电锅炉热交换器表面的候选涂层材料，通过2 kW光纤激光器将非晶/玻璃形成Fe-Cr-B合金NanoSteel SHS 7170沉积到锅炉级钢基底（15 Mo 3）上。进行了28次单轨道优化运行的综合试验，以开发三个加工参数（激光功率、激光横移速度和粉末进料速率）对粉末沉积效率、稀释度和孔隙率的影响的模型。结果发现，沉积效率取决于激光功率和粉末进料速率，当在激光功率范围为0.4至2 kW的参数窗口内进行测试时，随着功率的增加和粉末进料速率的降低而增加;横向速度从150至1200 mm min-1变化;粉末进料速率从4至10 g min-1变化。类似地，发现稀释也取决于激光功率和粉末进给速率。在上述相同的参数窗口内，稀释度随着功率的增加而增加，并且随着粉末进料速率的增加而减小。这意味着通过工艺参数的选择，可以调整这些特性以适应其应用。孔隙率被认为是独立的工艺参数，而主要是依赖于原料材料。产生用于预测粉末原料内的孔隙率的模型，发现孔隙率为8.5%。这些模型用于成功生产优化的涂层。
As a candidate coating material for heat-exchanger surfaces in commercial power generation boiler, an amorphous/glass forming Fe-Cr-B alloy NanoSteel SHS 7170 was deposited by a 2 kW fibre laser onto a boiler grade steel substrate (15Mo3). A comprehensive trial with 28 single track optimisation runs was carried out to develop models of the influence of three processing parameters, laser power, laser traverse speed and powder feed rate, on powder deposition efficiency, dilution and porosity. It was found that deposition efficiency is dependent on laser power and powder feed rate, increasing with increasing power and decreasing powder feed rate when tested within the parameter window of laser power ranging from 0.4 to 2 kW; traverse speed varying from 150 to 1200 mm min‑1; and powder feed rate varying from 4 to 10 g min‑1. Similarly, it was found that dilution is also dependent on laser power and powder feed rate. Dilution increases with increasing power and decreases with increasing powder feed rate within the same parameter window discussed above. This means that through processing parameter selection, these properties can be adjusted to suit their application. Porosity was found to be independent of processing parameters and instead mostly dependent on the feedstock material. A model was produced for predicting porosity within a powder feedstock, found to be 8.5%. These models were used to successfully produce an optimised coating.