Brazing diamond grits onto AA7075 aluminium alloy substrate with Ag–Cu–Ti filler alloy by laser heating
Brazing diamond grits onto AA7075 aluminium alloy substrate with Ag–Cu–Ti filler alloy by laser heating
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DOI：
10.1016/j.cja.2020.07.005
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发表时间：
2020-08
影响因子：
5.7
通讯作者：
G. Huang;Yingda Wang;M. Zhang;Changcai Cui;Z. Tong
中科院分区：
文献类型：
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作者：
G. Huang;Yingda Wang;M. Zhang;Changcai Cui;Z. Tong
金刚石钎焊是制造用于高效加工和精密磨削的砂轮的一种有前景的方法。这项工作研究了通过激光熔焊将金刚石磨粒粘合到具有 Ag-Cu-Ti 填充合金的铝合金 7075 (AA7075) 基底上的可行性。研究了钎焊金刚石接头的界面微观结构和强度。钎焊金刚石接头的截面由熔融填充合金层、熔池、热影响区、柱状晶区和等轴晶区组成。在填充合金/基体金属界面内，观察到的微观结构可能是 Ag(s.s)、Al(s.s)、TixAl、Al2Cu 和 Mg 金属间化合物。在金刚石/填充合金的结合界面处发现了一层厚度约为30-50nm的TiC。钎焊接头的平均峰值剪切力约为 39.8N。磨损磨削试验表明金刚石/AA7075 钎焊接头足以进行磨削。然而，发现砂粒脱落是此类钎焊接头的主要故障。这项工作拓宽了钎焊金刚石技术以及钎焊金刚石砂轮高效磨削的应用范围。
The brazing of diamond is a promising way to fabricate grinding wheels for efficient machining and precision grinding. This work investigated the feasibility of bonding diamond grits onto Aluminium Alloy 7075 (AA7075) substrate with a Ag–Cu–Ti filler alloy via laser fusion brazing. The interfacial microstructures and the strength of the brazed diamond joints were studied. The cross-section of the brazed diamond joint consists of a molten filler alloy layer, a molten pool, a heat effect zone, a columnar crystal zone and an equiaxed crystal zone. Within the interface of the filler alloy/substrate metal, microstructures observed possibly were Ag(s.s), Al(s.s), TixAl, Al2Cu and Mg intermetallic compounds. A layer of TiC with a thickness of about 30–50 nm was found at the bonding interface of the diamond/filler alloy. The averaged peak shear force of the brazed joints was found to be approximately 39.8 N. The abrasion grinding test indicated that the diamond/AA7075 brazed joint was adequate for grinding. However, the pulled-off of grit was found to be the primary failure of this type of brazed joint. This work broadened the brazing diamond technique and the range of applications of brazed diamond wheels for efficient grinding.