表面技术
錶麵技術
표면기술
SURFACE TECHNOLOGY
2015年
8期
44-48,75
,共6页
激光熔覆%TC4钛合金%h-BN%自润滑涂层%摩擦系数%耐磨性能
激光鎔覆%TC4鈦閤金%h-BN%自潤滑塗層%摩抆繫數%耐磨性能
격광용복%TC4태합금%h-BN%자윤활도층%마찰계수%내마성능
laser cladding%TC4 titanium alloy%h-BN%self-lubricating coatings%friction coefficient%Wear resistance
目的：优化钛合金激光熔覆固体润滑涂层的熔覆工艺参数,提高钛合金表面耐磨性能。方法采用Nd：YAG激光器,分别在高功率和低功率条件下,在TC4钛合金表面制备h-BN固体自润滑涂层。观察分析熔覆陶瓷层的宏观形貌、物相组成、显微组织和硬度,采用摩擦磨损试验仪对熔覆层的摩擦学性能进行研究。结果低激光功率下,熔覆材料上浮流失严重,熔覆层的相成分主要是TiN,TiB,TiB2等硬质相,硬度较高,存在裂纹。高激光功率下,基材的熔化稀释较好地抑制了润滑相h-BN的上浮,减少了溅射损失,发生了包晶反应,生成了单质金属Ti,熔覆层硬度低,但摩擦磨损试验表明,涂层中润滑相h-BN含量的增加使得形成了更好的润滑膜,降低了摩擦系数。结论在输出电流400 A,脉宽5 ms,频率12 Hz,扫描速度120 mm/min,搭接率50%~60%的条件下进行激光熔覆,所得熔覆层的表面状态平整,耐摩擦性能最好。
目的：優化鈦閤金激光鎔覆固體潤滑塗層的鎔覆工藝參數,提高鈦閤金錶麵耐磨性能。方法採用Nd：YAG激光器,分彆在高功率和低功率條件下,在TC4鈦閤金錶麵製備h-BN固體自潤滑塗層。觀察分析鎔覆陶瓷層的宏觀形貌、物相組成、顯微組織和硬度,採用摩抆磨損試驗儀對鎔覆層的摩抆學性能進行研究。結果低激光功率下,鎔覆材料上浮流失嚴重,鎔覆層的相成分主要是TiN,TiB,TiB2等硬質相,硬度較高,存在裂紋。高激光功率下,基材的鎔化稀釋較好地抑製瞭潤滑相h-BN的上浮,減少瞭濺射損失,髮生瞭包晶反應,生成瞭單質金屬Ti,鎔覆層硬度低,但摩抆磨損試驗錶明,塗層中潤滑相h-BN含量的增加使得形成瞭更好的潤滑膜,降低瞭摩抆繫數。結論在輸齣電流400 A,脈寬5 ms,頻率12 Hz,掃描速度120 mm/min,搭接率50%~60%的條件下進行激光鎔覆,所得鎔覆層的錶麵狀態平整,耐摩抆性能最好。
목적：우화태합금격광용복고체윤활도층적용복공예삼수,제고태합금표면내마성능。방법채용Nd：YAG격광기,분별재고공솔화저공솔조건하,재TC4태합금표면제비h-BN고체자윤활도층。관찰분석용복도자층적굉관형모、물상조성、현미조직화경도,채용마찰마손시험의대용복층적마찰학성능진행연구。결과저격광공솔하,용복재료상부류실엄중,용복층적상성분주요시TiN,TiB,TiB2등경질상,경도교고,존재렬문。고격광공솔하,기재적용화희석교호지억제료윤활상h-BN적상부,감소료천사손실,발생료포정반응,생성료단질금속Ti,용복층경도저,단마찰마손시험표명,도층중윤활상h-BN함량적증가사득형성료경호적윤활막,강저료마찰계수。결론재수출전류400 A,맥관5 ms,빈솔12 Hz,소묘속도120 mm/min,탑접솔50%~60%적조건하진행격광용복,소득용복층적표면상태평정,내마찰성능최호。
ABSTRACT:Objective To optimize the process parameters for laser cladding of solid self-lubricating coatings on titanium alloy, and improve the surface wear resistance of titanium alloy. Methods Using the Nd: YAG laser, h-BN ( hexagonal boron nitride) solid self-lubricating coatings were prepared on the surface of TC4 titanium alloy under conditions of high power and low power, re-spectively. The macro morphology, layer phase composition, microstructure, hardness and wear resistance of the ceramic layer were analyzed, and the tribological property of the ceramic layer was studied using a friction and wear tester. Results At low laser power, there was severe floating loss of cladding material, and the phase composition of the cladding layer was mainly composed of TiN, TiB, TiB2 and other hard phase components, the hardness was relatively high, with the presence of cracks. At high laser power, melting of the substrate inhibited the floating of the lubricating phase h-BN, reducing the sputtering loss, and peritectic re-action occurred, generating elemental metal Ti, the hardness value of the cladding layer was low, but the friction and wear tests showed increased h-BN content in the lubricating phase led to better formation of lubricating coating, further reducing the friction coefficient. Conclusion Under the condition of output current 400 A, pulse width 5 ms, 12 Hz frequency, scanning speed 120 mm/min, overlapping rate 50% ~60%, the surface state of the laser cladding coating obtained was smooth and flat, and the fric-tion resistance was the best.
