After years of hard work, his business plan finally materialized.

materialized 是动词 materialize 的过去式。materialize 由名词 material（物质）加上动词后缀 -ize 构成，字面意思是"使物质化"，引申为"实现、具体化"的意思。这里表示商业计划从构想变成了现实。