激光重熔含25％WC的铁基合金涂层的研究

Research on Coating of Iron Base Alloy Containing 25％ WC Remelted by Laser Beam

利用高能量密度的激光束重熔含25％WC的铁基合金涂层时,提高激光束能量密度有利于重熔层的成形,但是能量密度太高时,重熔层组织中的WC硬质相发生溶解。因此,必须选择合适的激光重熔工艺参数。在本试验条件下合适的工艺参数是:激光功率2.5kW、扫描速度25mm/s,激光束宽度4mm,激光重熔层的显微组织中的CrB、Cr_(22)C_6等微粒硬质相的存在使镶嵌WC的基体组织得到强化。激光重熔含25％WC的铁基合金涂层的抗脆断性能及其与基材的结合性能和抗磨粒磨损性能都明显地优于火焰喷涂层和火焰重熔层。

When the coating of iron base alloy containing 25％WC is remelted by laser beam, increasing laser energy density is favourable for the shape of remelted coating, but the hard WC phase in the remdted coating will dissolve if the laser energy density is too high, So that, the suitable paramenters for laser remelted should be chosen. The suitable parameters for laser remelting under the experiment are as follows: laser power 2.5kW. scanning speed 25mm/s, laser beam width 4mm. The hard particle phases CrB, Cr_(23)C_6 in the microsturcture of laser remelting coating lead to the strenthening of the matrix. The remelting coating's property for resistanoe to brittle fracture, its property for bonding with base metal and its property for resistance to particle erosion are obviously better than those of flame spraying coating and the coating remelted by flame.