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1.
由于粘胶结合强度的限制,常规拉伸法不能用于评价高强度涂层.利用对称切口拉伸的方'法,评价了不同喷涂和烧结工艺所得高强度涂层与基体的结合性能.结果表明,涂层与基体切口尖端的应力集中作用,使交界面产生裂纹并迅速扩展,导致涂层界面开裂.对应不同切口结构工艺参数,采用平面应力有限元对涂层/基体交界面上的应力分布进行了力学计算.结果表明:楔形切口和深U形切口两种情形下对涂层/基体交界面应力分布影响不大;沿界面方向的应力对涂层破坏有加速作用,切口尖端应力集中随切口切割深度的增大而减小.  相似文献   

2.
采用物理气相沉积法在Cr12MoV钢基体上制备了TiN涂层,利用扫描电镜、能量色散谱、X射线衍射和轮廓仪对涂层形貌特征、化学元素、物相组成和表面粗糙度进行了表征,用划痕法测试其结合强度,并分析划痕法涂层失效过程.通过往复磨损试验考察了其摩擦磨损性能,对涂层磨损机理进行了讨论.结果表明,TiN涂层主要组成相为TiN,试样表面粗糙度Ra值为328.91nm,涂层表面显微硬度达到2100 ~ 2200 HV;涂层厚度约为5μm,与基材之间存在一定的混合界面,其界面结合强度为28.85 N;在干滑动磨损实验条件下摩擦系数为0.45~0.52,涂层具有优异的耐磨性,其磨损机制主要为磨粒磨损.  相似文献   

3.
铜基体上制备ZrO2-NiCrAlY梯度喷涂层的组织及其性能   总被引:1,自引:0,他引:1  
功能梯度涂层能提高涂层与基体问的结合力、耐磨性,以往对铜基体上喷涂功能梯度涂层的研究较少.用等离子喷涂法,在铜基体上制备了zrO2-NiCrAlY梯度涂层.利用扫描电镜对涂层的组织形貌、成分进行了分析,对涂层的结合强度和抗热震性能进行了试验研究,并对试样进行了高温扩散处理.结果表明,梯度涂层设计合理,实现了成分和组织的连续梯度变化;与双层涂层相比,梯度涂层的结合强度和抗热震性有显著提高,涂层的结合以机械结合为主,梯度涂层内部是基体-涂层体系中最薄弱的环节;600℃热处理后,基体与涂层之间出现了扩散层.  相似文献   

4.
放电等离子烧结技术制备 Ti合金表面 HA活性涂层   总被引:5,自引:0,他引:5  
采用放电等离子烧结(SPS)技术,低温、快速地在Ti合金表面制备HA活性涂层。研究了涂层成分和厚度对涂层与基体结合强度的影响,观察了断口形貌。结果表明:随着涂层厚度的减小,结合强度提高;梯度涂层能提高涂层与基体的结合强度;特别是经钝化处理后烧结的试样,涂层与基体的结合强度显著提高,最高达到了64MPa,超过目前使用的生物涂层种植体材料的指标。  相似文献   

5.
电沉积镍涂层的制备及其抗冲击性能   总被引:1,自引:0,他引:1  
介绍了一种在低碳钢带基体上制备电沉积镍涂层的方法,并研究了这种涂层的抗冲击性能.镀镍液主要是硫酸盐溶液,镀层厚度为3~6 μm,电镀后用真空热处理使镍涂层与基体间形成界面过渡层.为了考察这种复合材料的抗冲击性能,在57气体炮上用平头弹和尖头弹冲击试样,然后用扫描电镜对冲击后的表面和界面进行检测,对冲击波理论冲击过程中的应变率与冲击应力进行了计算.结果表明,镍涂层在平头弹的冲击下未出现涂层表面的脱落和损伤,在尖头弹冲击下未出现涂层与基体的界面开裂现象,其动载体能比进口的SPCE材料好.研究表明,自制的涂层与基体结合强度高,涂层的耐冲击性能好,可在工业上应用.  相似文献   

6.
仿生磷灰石涂层与钛基体结合强度的划痕法实验   总被引:2,自引:0,他引:2  
本文采用碱热处理及SBF浸泡的方法在钛片上制备了仿生磷灰石涂层,并采用AES进行表面成分-深度分析,划痕法测定磷灰石涂层与基体的结合强度.结果显示,经碱热处理而制得的钛表面仿生磷灰石涂层与基体结合的界面为成分梯度界面,二者的结合要通过成分含量呈梯度变化的过渡层:Ca、P元素的含量从表面到基体逐渐下降,Ti元素的含量逐渐上升.热处理有利于提高涂层的基体结合强度,其原因是热处理使SBF中形成的磷灰石的晶核细小而均匀,使得表面涂层与基体之间的结合更为紧密.预钙化处理后形成的磷灰石涂层与金属之间仍为成分梯度界面,因此对涂层的基体结合强度影响不大.  相似文献   

7.
简要论述涂层力学性能的几种测定技术,介绍新研制的测定涂层力学性能专用试验机的系统,功能特点及测试方法.主要包括涂层显微硬度压痕,扭转试验,涂层断裂强度,抗剪切强度,结合强度的测定,涂层杯突试验技术,这些技术应用为评价涂层/基体界面材料性能和改进涂层质量提供一种量化测试手段.  相似文献   

8.
为进一步提高骨修复材料的骨诱导性能,引入了BaTiO_3压电涂层。首先,通过等离子喷涂法在Ti基体上制备羟基磷灰石(HA)、Ti-HA和Ti-HA-BaTiO_3这3种生物涂层;然后,采用正交试验设计优化了喷涂工艺参数,用SEM/EDS对涂层的形貌和成分进行了表征,并通过划痕试验测试了涂层与基体的结合强度;最后,进行了细胞培养试验,用CCK-8法对细胞毒性进行了评价,并在SEM下观察了细胞的粘附形态。结果显示:细胞带有伪足,呈梭形和不规则多边形,且粘附在Ti-HA-BaTiO_3复合涂层表面;细胞伸展形态良好,涂层的细胞毒性等级不高于1级。可见,Ti-HA-BaTiO_3复合材料可以作为临床植入材料应用。  相似文献   

9.
采用喷涂法和溶胶-凝胶法相结合的工艺,以FeAlNi混合粉体为过渡层材料在钢基体表面制备了Fe/Al2O3梯度涂层,并对其微观结构与性能进行分析.结果表明:当烧结温度为1220℃时,梯度涂层与钢基体的界面结合强度达到25.3MPa,涂层主要由α-Al2O3,AlFeO3和NiFe2O4等物相组成.Fe/Al2O3梯度涂层与钢基体的结合主要通过吸附与扩散化合两种方式共同起作用.涂层中没有明显的孔洞和平整的界面,且有树枝状组织生成,涂层与钢基体实现良好的结合,这表明涂层成分的梯度化设计能够有效地缓和界面处的应力集中,改善涂层与钢基体的界面结合状态,提高涂层材料的使用性能.  相似文献   

10.
近十多年来工程界广泛应用金属喷涂技术,特别是等离子喷涂的涂层,不仅较大地改善了基体材料与涂层的结合力,而且对沉积粒子彼此之间的结合力也有显著的改善。随着用途扩大,精确地测定涂层机械性能就显得更为重要了。涂层-基体结合强度是涂层质量的常规检验指标之一。其测定方法是将等离于喷涂的涂层试样用胶粘剂和另一对偶试样(未喷涂层的)粘接在一起,进行拉伸试验。当胶粘剂对  相似文献   

11.
Magnesium-containing fluoridated hydroxyapatite (MgxFHA) coatings have been developed to improve the biological performances of fluoridated hydroxyapatite (FHA) coatings. The coatings are deposited on Ti6Al4V substrates via a sol-gel process. The interface between the coating and substrate is characterized by scanning electron microscopy, glow discharge optical emission spectroscopy and X-ray photoelectron spectroscopy for coating thickness, elemental distribution and chemical states. Pull-off test is used to evaluate the adhesion strength. The results show that the interdiffusion of elements happens at the coating/substrate interface. The incorporation of Mg ions into FHA coatings enhances the pull-off adhesion strength between the coating and the substrate, but no significant difference is observed with different Mg concentrations.  相似文献   

12.
D. Müller  E. Fromm 《Thin solid films》1995,270(1-2):411-416
TiN and Al coatings on substrates of high-speed steel, steel, aluminium and copper have been used to study mechanical properties of coating systems, especially the adhesion of the coating. The quantities measured are internal stress of the coating, determined by X-ray diffraction, the critical load of the scratch test, the microhardness obtained by the indenter technique, and the interface fracture energy, determined by a three-point bend test developed recently by the authors. The fracture energy, Gc, is a measure for the adhesion strength of a coating system. The effect of bias voltage, sputter cleaning and contamination of the substrates on the adhesion strength and other mechanical properties are investigated with the four methods mentioned. Each of the testing methods reveal only specific aspects of the behaviour of the coating systems. The data obtained depend on bulk properties of the film and the substrate material and on properties of the interface. Variation of the bias voltage can change them in quite different ways. In addition, the inter-relations between the adhesion strength of the coating and the failure behaviour of the three-point bend test samples are discussed.  相似文献   

13.
薄膜结合强度的刮剥式测量方法   总被引:2,自引:0,他引:2  
本文介绍了一种薄膜结合强度的新型测量方法~刮剥法的测量原理、特点以及应用范围。所谓薄膜结合强度的刮剥式测量方法(简称刮剥法),实际上是一个使用特制刮剥刀具、以类似于薄层金属刮削方式工作,并以从基底上剥离薄膜所需能量作为其结合强度量度的测量方法。刮剥法与现广泛使用的划痕式结合力测量法的区别主要表现为:(1)该法是一个能量测量方法,即以薄膜的剥离能量作为薄膜与基体的结合强度的描述;(2)测量时采用的是对膜/基界面的切向加载方式;(3)测量结果是对膜/基结合强度的直接描述,并对基底表面状态、材质等不敏感;(4)可以对其它方法无法进行测量的超硬材料薄膜,如金刚石和立方氮化硼等,进行结合强度测量。本文通过对刮剥过程中刮剥刀刃附近区域的受力分析,得出了成功实现沿界面剥离薄膜的必要条件以及刮剥法测试对试样的要求和应用范围。  相似文献   

14.
Electrical discharge machining (EDM) is an alternative-shaping route for manufacturing complex component shapes of hard and brittle materials such as hardmetals (WC-Co cemented carbides). It is well established that in these materials EDM typically induces a heat affected surface layer with poor integrity. This degradation effect may be compensated through specific post-EDM surface treatments either by thermomechanical means or material surface deposition. In the latter case, a key property for optimal performance is the level of coating to substrate adhesion and how this is affected by the EDM-induced surface. The main objective of this investigation was to evaluate the adhesion strength of TiN coatings on EDMed hardmetals. A series of hardmetal samples that had been subjected to different multi-pass sequential EDM levels were coated with TiN. Adhesion behavior was assessed using the indentation adhesion test and comparing the critical load for crack extension (P c) and the interfacial fracture toughness (K Ic,interface) to those exhibited by the TiN coating deposited on a ground and polished substrate (used as baseline control). Experimental results indicated that indentation adhesion increased with finer-executed EDM, almost reaching baseline level values. The results are discussed on the basis of the compromising EDM influence on both surface integrity of the substrate and tortuousness at the interface, the latter resulting in mechanical anchoring of the TiN coating to the hardmetal substrate.  相似文献   

15.
用涂层压入仪测定薄膜与基体结合强度的探讨   总被引:1,自引:0,他引:1  
用新颖的能连续加载、卸载并配有声发射监测的涂层压入仪 ,对薄膜与基体的结合强度进行了探讨。实验结果表明 ,膜或膜 /基破坏的声发射信号各有特点 ,可区分压入过程中 (含卸载 )开裂和剥落及其对应的载荷值。压入法的临界载荷 pc 为加载过程中使膜发生初始剥落的外载 ,用涂层压入仪可精确测定。 pc 值对基体硬度和表面粗糙度的变化敏感。故用涂层压入仪可以实现用压入法考察膜 /基结合强度  相似文献   

16.
本文介绍声发射技术在判断划痕临界载荷以推定膜层与基材结合情况的研究结果。实验的试样是玻璃基材真空蒸镀铝膜、软钢上电镀镍层以及不同硬度的钢样上离子镀超硬氮化钛膜层。在脆性硬质基材上无论镀软膜或硬膜,划痕试验中一旦监听到声发射信号即表明基材与膜层结合失效,此时的划痕载荷即为临界载荷。塑性基材镀软膜层直到划痕到基材也无声发射信号出现。超硬膜层与钢基材的划痕试验中,声发射信号出现时载荷往往低于临界载荷。两者的差值决定于超硬膜的厚度和膜层与基材的硬度差。  相似文献   

17.
In this work the behaviour of hard coated light-metal components was investigated when they are mechanically loaded. Three lightmetal alloys, Ti-6Al-4V, AlSi7Mg and AlMgSi0.5 and 100Cr6 steel (as a reference material) were coated by two different physical vapour deposition processes: radio frequency magnetron sputtering and electron beam evaporation. The coating materials utilised were CrN and TiN. Standard test methods with different loading conditions were used to evaluate the substrate/coating-combinations: the hardness test (applying a static normal load), the scratch test (applying a combination of a static normal and a static tangential force) and the impact test (applying a dynamic normal load). It was observed that the load support of coated materials depends on the loading conditions. The coated aluminium alloys showed poor load support under all loading test conditions but produced a higher surface hardness than uncoated steel. Coated Ti-6Al-4V showed very good load support properties, similar to coated steel. All coated light-metal substrates demonstrated significant improvement in load support behaviour with an increase in coating thickness. The results of the scratch test, which is commonly used to asses adhesion properties of thin coatings, showed an immediate indenter-breakthrough on the aluminium alloy substrates, but causing no coating delamination. Due to this behaviour, the scratch test is not suitable to evaluate adhesion properties on coated soft light-metals. Yet the impact test allowed assessment of coating delamination on the aluminium alloys, proving its usefulness for adhesion measurement even on soft substrates. The study indicates that substitution of steel with coated lightmetal alloys is a viable proposition for certain applications.  相似文献   

18.
In this work an investigation was carried out on adhesion strength and micro-hardness of plasma sprayed coatings on Al-6061 and cast iron substrate materials. For the adhesion test, ASTM C633, and for the micro hardness, ASTM E384 standards were used. From the results obtained it was found that the main failure locations were in the bond coat-substrate interface, which is considered as adhesion strength. The various parameters affecting adhesion strength are also discussed.  相似文献   

19.
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