客户成功案例
West Australian Heavy Industries Benefit From Direct-Diode Laser Technology
APEX ETG uses Coherent 10 kW direct-diode lasers for efficient, high-speed cladding of components for industries such as mining, energy and construction.
Daniel Rhind has worked with surface coatings for 20 years and is keenly aware of the advantages of laser cladding over other methods for repairing worn metal parts. In fact, he’s so enthusiastic about laser cladding that he started his own company – APEX ETG – to bring the benefits of the technology to industries in Western Australia.
但作为一名企业主，他对成本和生产效率的重视程度，丝毫不亚于对成果质量的重视。因此，为了保持竞争力，他的激光堆焊设备必须满足多项不同要求。
首先，它必须能够快速铺设。这使他能够在满足客户要求的时限内，完成石油天然气、采矿和建筑行业中大量大型部件的表面翻新工程。
此外，他还要求生产过程具有灵活性。他希望车间里的每套覆层系统都能承担尽可能广泛的任务——这样每套系统都能持续运转。这能最大限度地提高生产效率和投资回报率。如果他能在不同工序之间切换设备时，将停机时间和操作难度降至最低，生产效率将进一步提升。
影响生产效率的另一个重要因素是设备的可靠性和运行时间。如果激光堆焊机处于停机状态，就无法创造收入，也无法收回成本。
最后，毋庸置疑的是，他需要提供高质量的服务成果。APEX ETG 的成功在很大程度上依赖于回头客——例如，为矿业公司提供的液压缸翻新长期项目。他只有通过提供质量上乘的服务、快速的周转时间，当然还有合理的价格，才能留住这些客户。“客户的成功就是我们的成功，”丹尼尔解释道。
To meet all these needs, APEX ETG depends on laser cladding systems based on Coherent HighLight DD series products. These are diode-lasers that offer up to 10 kW of output power. They produce a free space (rather than fiber-coupled) beam that can readily be formed into a rectangular shape over a wide range of dimensions. A simple change in the beam delivery optics can produce beams of anywhere from 1 mm to 12 mm in width and 6 mm to 36 mm in length. Both pressurized and gravity feed powder nozzles are also available from Coherent to support high deposition rate cladding.
直接二极管的优势
“If you asked most people in my industry, and especially the vendors that sell this equipment, they would tell you that the best tool for a large area cladding shop is a fiber-coupled diode laser. They would say you can take one fiber-coupled diode laser and then connect it to various processing heads as needed to perform different jobs,” notes Daniel. “But, as someone who has done a lot of laser cladding, I can tell you that is exactly the wrong answer. The problem occurs with job changeovers. If I’m doing one job with a 6 mm long line beam, and the next job requires an 18 mm beam, then I have to change to a different cladding head. That requires realignment and adjustment – and that takes time.”
“The common perception is that someone can buy a single fiber-coupled diode-laser system and a bunch of different process heads and then they can do everything. And maybe they can – but they can’t do it fast and efficiently. And when that equipment is down for changeovers, you’re not making money. That limits your ability to do high-speed, large-area cladding,” he adds.
“In contrast, using the HighLight DD, I just swap the optics in the process head to change line dimensions – and start the process again. It literally only takes a moment. And I can get laser lines long enough to clad even really large areas in a timeframe that makes economic sense.”
“当然，我并不是说光纤耦合系统有什么问题。我自己就拥有好几套，而且使用频率很高。对于低价值零件的小面积堆焊而言，它们确实是经济实惠的工具。但它们并不能提供人们常说的灵活性。而且，对于大面积堆焊任务——这已成为APEX ETG业务的重要组成部分——它们显然并不合适。用于此类任务，从经济角度来看并不划算。”
外墙饰面的实际应用
The 10 kW Coherent HighLight DD direct-diode laser has enabled APEX ETG to perform cladding jobs which have never been done before in Western Australia – and maybe nowhere else in the entire world. One example is “hardfacing” a mining excavator “bucket.” This is the huge scoop on the excavator that picks up earth. The particular bucket presented to APEX ETG had a volume of 42 m³ – quite literally the size of a school bus.
这些铲斗在使用过程中会磨损，最终需要通过铺设新材料来修复表面，以保持其可用性。过去，这意味着要在铲斗上焊接厚实的碳化铬/钨“耐磨板”。每块板的尺寸约为3米×1米，因此需要相当数量的板材才能覆盖整个铲斗表面。
但焊接耐磨板存在一些显著的缺点。首先，这是一个耗时且劳动密集型的过程。其次，它会使铲斗增加大量额外重量——更确切地说，仅这款铲斗的耐磨板组件就重达9吨。
将平坦的耐磨板焊接到铲斗的曲面上会带来一些额外的问题。这些板材因被弯曲而处于受力状态，有时在使用过程中会弹回脱落。这意味着挖掘机必须停机，以便将板材重新焊接回去。此外，这还存在一个重大的安全隐患。当板材弹回脱落时会产生巨大的冲击力，这可能导致工人受伤。
To perform laser cladding, APEX ETG mounted the bucket on a large robotic platform. This allowed the laser beam to move continuously and cover the entire surface with cladding. This took much less time than a typical repair using welding.
铲斗上安装的护板总重量为450公斤。这意味着，与安装了耐磨板的铲斗相比，每次铲土时，挖掘机可额外装载8.5吨物料。这不仅提高了设备的工作效率，还显著降低了燃油成本。
采用直接二极管系统进行的堆焊在质量上也毫不妥协。事实上，情况恰恰相反。在APEX ETG进行硬面堆焊的铲斗已运行了5,000小时，激光堆焊表面未受任何影响。此外，激光堆焊不存在安全隐患，因为新形成的表面不会脱落。
“This job is an extreme example,” notes Rhind. “It’s quite possibly the largest part ever clad. And it would just be utterly impossible to get this same level of results with any other technology. So, it really highlights the extraordinary capabilities of a high-power, direct-diode laser to bring the benefits of cladding to the very large parts that are common in construction, oil and gas, mining, and other heavy industrial sectors.”
“But, APEX ETG’s laser cladding capabilities cater to applications of all sizes and geometries. This enables us to service the needs of a wide range of industries within Western Australia. It is thanks to our strong relationship with Coherent that we are able to bring this technology into the market.”
“Laser cladding almost universally provides the best way to resurface a worn metal part, and nothing matches the Coherent 10 kW direct-diode laser for economical, rapid cladding of large parts."
——丹尼尔·林德，APEX ETG 董事总经理
什么是激光熔覆
堆焊是一种增材制造工艺，广泛应用于多个行业，用于改善零件的表面性能，或对因使用而磨损的部件进行表面修复。堆焊是指在基体上形成一层与基体材料成分不同的新表面层。
覆层工艺有多种不同的方法，每种方法在所用材料、覆层质量以及包括生产速度、工艺兼容性和成本在内的各种实际问题方面，都具有各自的独特特点。
某些方法涉及某种形式的电弧焊接，例如钨极气保护电弧焊（GTAW）、等离子弧焊（PAW）、等离子转移电弧焊（PTA）、气体金属电弧焊（GMAW）、埋弧焊（SAW）以及其他几种方法。
在所有这些工艺中，电弧都会熔化母材的表面。随后，以焊丝或粉末形式加入的堆焊材料也被电弧熔化。它与母材熔池混合，然后重新凝固形成堆焊层。
Another approach is thermal spraying. Here, the powdered clad material is melted by a flame or electricity, and then sprayed on to the workpiece. The workpiece is only heated to <200°C. The four most common types of thermal spraying are flame spraying, arc spraying, plasma spraying and high-velocity oxyfuel (HVOF).
激光堆焊与电弧焊接方法类似。激光会同时熔化基体表面和堆焊材料，后者可以是焊丝、带材或粉末形式。
然而，与所有这些其他技术相比，激光堆焊具有显著的优势。与焊接方法类似，激光堆焊层与基体形成了真正的冶金结合。这意味着堆焊层具有极高的耐久性，不会出现剥落或分层现象，并具备出色的耐磨性和耐腐蚀性。而热喷涂方法则无法达到这一效果。
然而，与电弧焊接不同，激光并不会显著加热工件的主体部分。这既避免了因热效应导致的工件变形，也省去了为纠正这种变形而进行的后续处理工序。电弧焊接过程中产生的热量还会导致挥发性合金元素蒸发，并可能在某些材料中引起表面硬化。
图1.激光熔覆是一种修复磨损金属部件的高效方法。
Figure 2. Cladding with a Coherent HighLight DD series laser, which produces a free space beam that can readily be formed into a long line, enables coverage of large areas in a timeframe that makes economic sense.
图3.为矿业公司翻新液压缸是APEX日常业务的一部分。