选择性激光熔化（SLM）中，为什么扫描策略和层间重叠很关键，否则会产生哪些缺陷？
In selective laser melting (SLM), why are scan strategy and inter-layer overlap critical, and what defects arise if they are wrong?
激光快速熔凝形成极大的温度梯度和残余应力，扫描路径决定了应力方向和散热。策略不当会引起球化、未熔合、裂纹和翘曲，因此常用棋盘式或旋转扫描来均衡热量。
Rapid melting creates steep temperature gradients and residual stress, and the scan path sets stress direction and heat dissipation. Poor strategy causes balling, lack of fusion, cracking and warping, so checkerboard or rotated scans are used to balance heat.
难度 专业 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
Gibson、Rosen & Stucker，《增材制造技术：从快速原型到直接数字化制造》（第2版）
Gibson, Rosen & Stucker, 'Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing' (2nd ed.)
#SLM #扫描策略 #残余应力
生物3D打印如何用“生物墨水”把活细胞打印成组织，打印后细胞为什么还能存活？
How does bioprinting use bio-ink to print living cells into tissue, and why do the cells survive the process?
生物墨水是把细胞混在温敏水凝胶里，低温和温和剪切力保护细胞不被挤死，打印后凝胶固化成支架。细胞嵌在孔隙中继续代谢，并靠营养液灌注维持成活，等待血管长入。
Bio-ink suspends cells in a temperature-sensitive hydrogel; low temperature and gentle shear protect them, and the gel solidifies into a scaffold after printing. Cells sit in pores, keep metabolizing under perfusion, and await blood-vessel ingrowth.
难度 专业 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Murphy & Atala，《组织与器官的3D生物打印》，《自然·生物技术》32卷，773–785页（2014）
Murphy, S.V. & Atala, A. '3D bioprinting of tissues and organs.' Nat. Biotechnol. 32, 773–785 (2014)
#生物3D打印 #生物墨水 #组织工程
金属3D打印为什么需要给悬空的部分打印脚手架?打印完怎么拆?
Why does metal printing need scaffolds under overhangs — and how are they removed?
激光粉末床逐层熔粉时,新熔化的金属会因表面张力球化、因收缩翘曲,悬空面没有下方材料托底必然失败;同时传热也依赖下方实体把热带入基板。因此超过约45度角的悬垂都要加支撑:块状或格子状的临时柱子。它们不是白给的——去除支撑需要线切割、手工打磨甚至五轴加工,支撑区留下粗糙疤痕;每根支柱还消耗材料与时间。前沿方向是无支撑打印:倾斜重排零件方向、自适应切片压低悬垂角,或用可溶解牺牲材料做智能脚手架。
In laser powder-bed fusion, fresh melt pools ball up from surface tension and warp from shrinkage; unsupported overhangs have no material beneath to anchor or conduct heat into the plate. Overhangs beyond roughly forty-five degrees therefore get supports — blocky lattice columns. They are not free: removal needs wire EDM, hand finishing even five-axis machining, leaves scars, and eats material and time. Frontiers fight back — reorienting parts so overhang angles stay legal, adaptive slicing, or sacrificial soluble ceramic scaffolds as smart formwork.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
DebRoy、Wei、Zuback 与 Mukherjee,《Additive manufacturing of metallic components – Process, structure and properties》,Progress in Materials Science,2018 (DOI: 10.1016/j.pmatsci.2017.10.001)
DebRoy, Wei, Zuback & Mukherjee, 'Additive manufacturing of metallic components – Process, structure and properties', Progress in Materials Science, 2018, DOI: 10.1016/j.pmatsci.2017.10.001
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1016/j.pmatsci.2017.10.001
#支撑结构 #悬垂角 #粉末床熔融
增材制造里的“拓扑优化”是什么意思，为什么它和传统减重设计思路不一样？
What does topological optimization mean in additive manufacturing, and why is it different from traditional weight-reduction design?
拓扑优化让计算机按载荷路径把多余材料“掏空”，只留下受力必需的骨架，得到像树枝或海绵一样怪异却高效的结构。这种有机形状用传统切削很难做出，正好发挥增材制造的自由度。
Topology optimization lets a computer remove material along load paths, leaving only the skeleton that must carry force—strange but efficient tree- or sponge-like shapes. Such organic forms are hard to machine but ideal for additive freedom.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
Gibson、Rosen & Stucker，《增材制造技术：从快速原型到直接数字化制造》（第2版）
Gibson, Rosen & Stucker, 'Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing' (2nd ed.)
#拓扑优化 #轻量化 #generative-design
建筑用的混凝土3D打印，为什么层与层之间容易开裂、需要控制挤出速度和养护？
Why do construction-grade concrete 3D prints tend to crack between layers, and why must extrusion speed and curing be controlled?
每一层是新拌砂浆，靠水泥水化把上下层“粘”在一起；若下层还没硬、上层已堆叠，就会软塌或层间剥离。控制挤出节奏、加纤维和及时养护能让层间粘结更牢。
Each layer is fresh mortar that bonds to the one below through cement hydration; if the lower layer is still soft when the next is stacked, it sags or delaminates. Controlling extrusion pace, adding fibers and curing promptly strengthen inter-layer bonding.
难度 进阶 · 适合 小学低段(6-8)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
Gibson、Rosen & Stucker，《增材制造技术：从快速原型到直接数字化制造》（第2版）
Gibson, Rosen & Stucker, 'Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing' (2nd ed.)
#混凝土打印 #层间粘结 #养护
金属3D打印件早期为什么被航空业拒收,现在却能装进发动机?
Why did the aviation industry once reject metal 3D-printed parts — and how did they end up inside jet engines today?
激光选区熔化把粉末层层熔凝,早期工艺的层间未熔合、气孔与残留应力让疲劳寿命离散巨大,适航审定无从下手。转机来自三件事:工艺窗口的系统优化(功率-速度-铺粉厚度匹配)、原位监测与X射线探伤实现全检,以及按打印特性重新设计零件——GE燃油喷嘴把二十个零件合成一体,内部冷却通道传统机加工无法完成,重量减25%、寿命提升五倍,装机已逾十万个。增材不是替代切削,而是为「一体化加内流道」的设计自由度买单。
Early laser powder-bed fusion parts suffered lack-of-fusion defects, porosity and residual stress that scattered fatigue lives too widely for airworthiness certification. Three fixes turned the tide: systematic process-window optimization matching power, speed and layer thickness; in-situ monitoring plus full X-ray inspection; and redesigning parts for the process — the GE fuel nozzle merged twenty components into one with internal cooling passages impossible to machine conventionally, cutting weight 25 percent and multiplying life fivefold, with more than a hundred thousand already flying. Additive manufacturing complements machining by buying design freedom: integration and internal channels.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Gibson、Rosen 与 Stucker,《Additive Manufacturing Technologies》第2版,Springer,2015
I. Gibson, D. Rosen and B. Stucker, Additive Manufacturing Technologies, 2nd ed., Springer, 2015
独立核验依据 · Independent verification: 核验依据 1 ISBN 9781493921133 (2016)
#增材制造 #疲劳寿命 #一体化设计
金属3D打印为什么通常要把零件埋在金属粉末里逐层熔化，而不是直接“打印”成实心？
Why is metal 3D printing usually done by melting parts layer by layer inside a bed of metal powder instead of directly printing solid objects?
金属粉末既是原材料也是支撑介质，每熔好一层就铺上新粉再熔下一层，这样悬空和复杂结构才不会塌陷。未熔的粉末还能回收重复使用。
The metal powder acts as both feedstock and support: each melted layer is covered with fresh powder for the next, so overhangs and complex shapes will not collapse. Unmelted powder is recovered and reused.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
Gibson、Rosen & Stucker，《增材制造技术：从快速原型到直接数字化制造》（第2版）
Gibson, Rosen & Stucker, 'Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing' (2nd ed.)
#增材制造 #金属3D打印 #粉末床