欧美色图片玖玖视频

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超聲波焊接原理

表面粗糙度及周期性結構表征

表面粗糙度測量

粗糙表面包括随机粗糙表面和结构有周期性变化的规则表面。可以用均方根表面粗糙度h和相关长度L予以描述。通常可以根据给定方向上的表面高度变化，用表面粗糙度仪来进行参数测定。但对于易损表面或其表面粗糙度在微米以下的表面测定，机械式表面粗糙度測量仪器已无能为力。超声波频谱分析仪是评价此类表面参数特征的有用工具。

背面反射方法和背散射法都可以用于表面粗糙度的測量。其中，背面反射法是評價表面粗糙度較爲簡單的方法，可采用常規的液浸法，測出聲束垂直入射至被測表面時的反射頻譜，並以光滑表面上獲得的頻譜爲參考基准，對測量頻譜作歸一化處理。其反射系數可寫成

式中，R₀为光滑表面的反射系数; c为浸液中的声速。

在浸液聲速c已知的條件下，利用歸一化反射系數，可以間接計算均方根表面粗糙度h。圖8-5是針對不同表面粗糙度的鋁試樣獲得的歸一化反射頻譜，可以看到，由式(8-5)計算得到的均方根表面粗糙度h隨頻率呈抛物線變化規律。

利用超聲波背散射法評價粗糙表面幾何外形的原理如圖8-6所示。采用脈沖回波方式進行測量，獲得粗糙表面背散射壓縮波的強度。圖8-7爲不同均方根表面粗糙度黃銅試樣上測得的典型背散射曲線圖。可以看出，在5MHz及15MHz下，背散射信號強度與利用表面光度儀測得的表面粗糙度之間有很好的對應關系。

灵科超声波坚持自主研发，最大力度投入研发设计，拥有一支近30年的研发制造团队，发明创造170余项专利新技术。主要品牌有LINGGAO灵高、LINGKE灵科、SHENGFENG声峰等。广泛运用在医疗器械、电子器材、打印耗材、塑料、无纺布、包装、汽配等多个领域，为海内外各行业、企业提供了大量稳定性强的优质超声波塑焊设备及应用方案。

超聲波焊接在家電設備的作用

超聲波點焊在汽配行業中的應用

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